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Sample records for vitro aortic ring

  1. Mechanisms involved in the vasorelaxant effects produced by the acute application of amfepramone in vitro to rat aortic rings

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    López-Canales, J.S. [Section of Postgraduate Studies and Investigation, Higher School of Medicine from the National Polytechnic Institute, Mexico City (Mexico); Department of Cellular Biology, National Institute of Perinatology, Mexico City (Mexico); Lozano-Cuenca, J.; Muãoz-Islas, E.; Aguilar-Carrasco, J.C. [Department of Cellular Biology, National Institute of Perinatology, Mexico City (Mexico); López-Canales, O.A.; López-Mayorga, R.M.; Castillo-Henkel, E.F.; Valencia-Hernández, I.; Castillo-Henkel, C. [Section of Postgraduate Studies and Investigation, Higher School of Medicine from the National Polytechnic Institute, Mexico City (Mexico)

    2015-03-27

    Amfepramone (diethylpropion) is an appetite-suppressant drug used for the treatment of overweight and obesity. It has been suggested that the systemic and central activity of amfepramone produces cardiovascular effects such as transient ischemic attacks and primary pulmonary hypertension. However, it is not known whether amfepramone produces immediate vascular effects when applied in vitro to rat aortic rings and, if so, what mechanisms may be involved. We analyzed the effect of amfepramone on phenylephrine-precontracted rat aortic rings with or without endothelium and the influence of inhibitors or blockers on this effect. Amfepramone produced a concentration-dependent vasorelaxation in phenylephrine-precontracted rat aortic rings that was not affected by the vehicle, atropine, 4-AP, glibenclamide, indomethacin, clotrimazole, or cycloheximide. The vasorelaxant effect of amfepramone was significantly attenuated by NG-nitro-L-arginine methyl ester (L-NAME) and tetraethylammonium (TEA), and was blocked by removal of the vascular endothelium. These results suggest that amfepramone had a direct vasorelaxant effect on phenylephrine-precontracted rat aortic rings, and that inhibition of endothelial nitric oxide synthase and the opening of Ca{sup 2+}-activated K{sup +} channels were involved in this effect.

  2. Mechanisms involved in the vasorelaxant effects produced by the acute application of amfepramone in vitro to rat aortic rings

    International Nuclear Information System (INIS)

    López-Canales, J.S.; Lozano-Cuenca, J.; Muãoz-Islas, E.; Aguilar-Carrasco, J.C.; López-Canales, O.A.; López-Mayorga, R.M.; Castillo-Henkel, E.F.; Valencia-Hernández, I.; Castillo-Henkel, C.

    2015-01-01

    Amfepramone (diethylpropion) is an appetite-suppressant drug used for the treatment of overweight and obesity. It has been suggested that the systemic and central activity of amfepramone produces cardiovascular effects such as transient ischemic attacks and primary pulmonary hypertension. However, it is not known whether amfepramone produces immediate vascular effects when applied in vitro to rat aortic rings and, if so, what mechanisms may be involved. We analyzed the effect of amfepramone on phenylephrine-precontracted rat aortic rings with or without endothelium and the influence of inhibitors or blockers on this effect. Amfepramone produced a concentration-dependent vasorelaxation in phenylephrine-precontracted rat aortic rings that was not affected by the vehicle, atropine, 4-AP, glibenclamide, indomethacin, clotrimazole, or cycloheximide. The vasorelaxant effect of amfepramone was significantly attenuated by NG-nitro-L-arginine methyl ester (L-NAME) and tetraethylammonium (TEA), and was blocked by removal of the vascular endothelium. These results suggest that amfepramone had a direct vasorelaxant effect on phenylephrine-precontracted rat aortic rings, and that inhibition of endothelial nitric oxide synthase and the opening of Ca 2+ -activated K + channels were involved in this effect

  3. Correction of aortic insufficiency with an external adjustable prosthetic aortic ring.

    Science.gov (United States)

    Gogbashian, Andrew; Ghanta, Ravi K; Umakanthan, Ramanan; Rangaraj, Aravind T; Laurence, Rita G; Fox, John A; Cohn, Lawrence H; Chen, Frederick Y

    2007-09-01

    Less invasive, valve-sparing options are needed for patients with aortic insufficiency (AI). We sought to evaluate the feasibility of reducing AI with an external adjustable aortic ring in an ovine model. To create AI, five sheep underwent patch plasty enlargement of the aortic annulus and root by placement of a 10 x 15 mm pericardial patch between the right and noncoronary cusps. An adjustable external ring composed of a nylon band was fabricated and placed around the aortic root. Aortic flow, aortic pressure, and left ventricular pressures were measured with the ring loose (off) and tightened (on). Mean regurgitant orifice area decreased by 86%, from 0.07 +/- 0.03 cm2 (ring loose, off) to 0.01 +/- 0.00 cm2 (ring tightened, on) [p < 0.01]. The regurgitant fraction decreased from 18 +/- 4% to 2 +/- 1% [p < 0.01]. The ring did not significantly affect stroke volume and aortic pressure. An ovine model of aortic root dilatation resulting in acute AI has been developed. In this model, application of an external, adjustable constricting aortic ring eliminated AI. An aortic ring may be a useful adjunct in reducing AI secondary to annular dilatation.

  4. New graft sizing rings for aortic valve reimplantation procedures.

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    Jelenc, Matija; Jelenc, Blaž; Kneževic, Ivan; Klokocovnik, Tomislav

    2018-01-01

    The objective was to design sizing rings that would enable proper sizing of the graft in reimplantation procedures and to perform leaflet repair before graft implantation. The rings were designed in Autodesk Fusion 360 (San Rafael, CA, USA) and 3D printed using a commercial online 3D printing service. We designed incomplete rings with a low profile and complete rings with a high profile. The complete rings are best suited for reimplantation procedures, whereas low profile C rings are intended for isolated aortic valve repair, where the ascending aorta is not transected. The rings come in sizes corresponding to Vascutek Gelweave graft sizes (Vascutek Terumo, Renfrewshire, Scotland). The ring internal diameters are 5% larger than the designated ring sizes and account for the 5% stretch of the grafts when pressurized. Blades of the rings are placed at 20° intervals. The slits between the blades are designed in such a way that the commissural U-sutures, when put in place and under tension, will lock the ring in position. The rings were successfully used in 10 of our latest reimplantation procedures. After dissection of the aortic root, the commissures were suspended with U-stitches and then the ring was seated onto them. Complete leaflet repair with plication to achieve adequate effective height was then performed, followed by graft implantation. No additional leaflet repair was needed. The newly designed sizing rings enable proper sizing of the graft in reimplantation procedures and enable complete leaflet repair before graft implantation. © The Author 2017. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

  5. Magnesium and diltiazem relaxes phenylephrine-precontracted rat aortic rings

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    Dogan, Mustafa; Peker, Recep O.; Donmez, Soner; Gokalp, Osman

    2012-01-01

    Perioperative vasospasm during cardiovascular surgery is a challenging problem. Several vasodilator agents are frequently utilized for its prevention in surgical practice. Magnesium and diltiazem both have known potential vasorelaxant effects. We planned to compare the efficacy of diltiazem and magnesium in relieving phenylephrine-precontracted rat aortic rings. Ten young adult female Wistar albino rats weighing 230–260 g were used in this study. The aortic rings in the organ bath equilibrated and reached their baseline tension. Precontraction was induced by 0.001 mmol/l phenylephrine and cumulative concentration–relaxation curves were obtained by consecutively increasing the addition of either diltiazem (10−6-0.1 mmol/l) or magnesium (0.1–10 mmol/l). The mean maximal relaxation responses observed by diltiazem and magnesium on separate aortic rings were 90 ± 3 and 53 ± 2%, respectively. The calculated EC50 of diltiazem was 0.01035 mmol/l, whereas the EC50 of magnesium was 4.064 mmol/l (P < 0.05). Both magnesium and diltiazem produced vasorelaxation on phenylephrine-precontracted rat aortic rings in this study, but the potency of diltiazem regarding the EC50 value was significantly higher than that of magnesium. Magnesium could be a candidate together with diltiazem to inhibit vasospasm on arterial grafts during coronary bypass surgery. PMID:22523136

  6. Deformation of the dog aortic valve ring during the cardiac cycle

    NARCIS (Netherlands)

    van Renterghem, R.J.; Steenhoven, van A.A.; Arts, M.G.J.; Reneman, R.S.

    1988-01-01

    Changes in strain in the line of aortic valve leaflet attachment (aortic ring) were measured during the cardiac cycle by means of an inductive technique. To that purpose coils were sutured to each commissure and base point of the aortic ring, when the animals were on a cardiopulmonary bypass. After

  7. Melatonin attenuates thiocyanate-induced vasoconstriction in aortic rings

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    Alexander M. Prusa

    2017-11-01

    Full Text Available Cigarette smoking not only has a carcinogenic effect but also leads to an increase in arterial blood pressure. Besides its main components, i.e. nicotine, tar, and carbon monoxide, cigarette smoke also contains thiocyanate. Thiocyanate anions (SCN− arise from the detoxification of hydrogen cyanide and its plasma concentrations were found to correlate significantly with cigarette consumption. There is also evidence that atherosclerotic disease progression is much more rapid when serum SCN− levels are increased. Melatonin, a non-toxic indolamine with various physiologic functions, is believed to protect against inflammatory processes and oxidative stress. It has been demonstrated that melatonin serves as free radical scavenger and represents a potent antioxidant. Therefore, it is believed that melatonin with its atheroprotective effects may be useful either as a sole therapy or in conjunction with others. The aim of this study was to quantify the thiocyanate-induced vasomotor response in aortic tissue and further to examine the potential of melatonin in affecting the generated vasoreactivity. Aortic rings of adult male normotensive Wistar rats were cut into 4-mm rings. Following the administration of thiocyanate in various concentrations, vasomotor response of aortic vessel segments was measured. To assess the effect of melatonin on vasomotor activity, organ bath concentrations were modulated from 60 to 360 pM, which corresponds to physiologic plasma up to the levels of patients with regular oral intake of 3 mg of melatonin as a supplement. Thirty-six rat aortic rings were studied. When exposed to thiocyanate, vessel segments revealed vasoconstriction in a concentration-dependent manner. In rings which were preincubated with melatonin at a concentration of 360 pM, a 56.5% reduction of effect size could be achieved (4.09 ± 1.22 mN versus 9.41 ± 1.74 mN, P < 0.0001. Additionally, administration of 360 pM melatonin at a

  8. Early results after implantation of a new geometric annuloplasty ring for aortic valve repair.

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    Mazzitelli, Domenico; Nöbauer, Christian; Rankin, J Scott; Badiu, Catalin C; Krane, Markus; Crooke, Philip S; Cohn, William E; Opitz, Anke; Schreiber, Christian; Lange, Rüdiger

    2013-01-01

    Aortic valve repair is associated with fewer long-term valve-related complications as compared with valve replacement, and repair is being performed increasingly. A current problem is the lack of a geometric annuloplasty ring to facilitate reconstruction. This paper describes the first clinical application of such a device designed to permanently restore physiologic annular size and geometry during aortic valve repair. Based on mathematical studies of human cadaver valves, as well as computed tomography angiographic analyses of awake patients with normal valves, a three-dimensional annuloplasty ring has been developed, consisting of low-profile, one-piece titanium construction and Dacron cloth covering. The ring design incorporates 2:3 elliptical base geometry and 10-degree outwardly flaring subcommissural posts. Appropriately sized rings were implanted in 5 patients with severe aortic insufficiency due to annular dilation and anatomic leaflet defects. The rings restored annular geometry and facilitated leaflet repairs in all patients. Each recovered excellent valve function with minimal residual leak. All patients convalesced uneventfully, were discharged within 7 days after surgery, and continue with stable valve function as long as 6 months after implantation. Initial clinical application of a geometric aortic annuloplasty ring was associated with excellent device performance and perhaps better repairs. Further clinical series and patient follow-up should identify potential benefits of the device, including improved applicability and stability of aortic valve repair. Copyright © 2013 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

  9. Vasorelaxant Effect of Osterici Radix Ethanol Extract on Rat Aortic Rings

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    Kyungjin Lee

    2013-01-01

    Full Text Available The root of Ostericum koreanum Maximowicz has been used as a traditional medicine called “Kanghwal” in Korea (or “Qianghuo” in China. The purpose of this study was to investigate the vasorelaxant activity and mechanism of action of an ethanol extract of the O. koreanum root (EOK. We used isolated rat aortic rings to assess the effects of EOK on various vasorelaxant or vasoconstriction factors. EOK induced vasorelaxation in phenylephrine hydrochloride (PE or KCl precontracted aortic rings in a concentration-dependent manner. However, the vasorelaxant effects of EOK on endothelium-intact aortic rings were reduced by pretreatment with L-NAME or methylene blue. In Ca2+-free Krebs-Henseleit solution, pretreatment with EOK (0.3 mg/mL completely inhibited PE-induced constriction. In addition, EOK (0.3 mg/mL also completely inhibited vasoconstriction induced by supplemental Ca2+ in aortic rings that were precontracted with PE or KCl. Furthermore, the EOK-induced vasorelaxation in PE-contracted aortic rings was inhibited by preincubation with nifedipine. These results indicate that the vasorelaxant effects of EOK are responsible for the induction of NO formation from L-Arg and NO-cGMP pathways, blockage of the extracellular Ca2+ entry via the receptor-operative Ca2+ channel and voltage-dependent calcium channel, and blockage of sarcoplasmic reticulum Ca2+ release via the inositol triphosphate pathway.

  10. Gallium-SPECT in the detection of prosthetic valve endocarditis and aortic ring abscess

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    O' Brien, K.; Barnes, D.; Martin, R.H.; Rae, J.R. (Department of Diagnostic Radiology, Victoria General Hospital Halifax, Nova Scotia (Canada))

    1991-09-01

    A 52-yr-old man who had a bioprosthetic aortic valve developed Staphylococcus aureus bacteremia. Despite antibiotic therapy he had persistent pyrexia and developed new conduction system disturbances. Echocardiography did not demonstrate vegetations on the valve or an abscess, but gallium scintigraphy using SPECT clearly identified a focus of intense activity in the region of the aortic valve. The presence of valvular vegetations and a septal abscess was confirmed at autopsy. Gallium scintigraphy, using SPECT, provided a useful noninvasive method for the demonstration of endocarditis and the associated valve ring abscess.

  11. Gallium-SPECT in the detection of prosthetic valve endocarditis and aortic ring abscess

    International Nuclear Information System (INIS)

    O'Brien, K.; Barnes, D.; Martin, R.H.; Rae, J.R.

    1991-01-01

    A 52-yr-old man who had a bioprosthetic aortic valve developed Staphylococcus aureus bacteremia. Despite antibiotic therapy he had persistent pyrexia and developed new conduction system disturbances. Echocardiography did not demonstrate vegetations on the valve or an abscess, but gallium scintigraphy using SPECT clearly identified a focus of intense activity in the region of the aortic valve. The presence of valvular vegetations and a septal abscess was confirmed at autopsy. Gallium scintigraphy, using SPECT, provided a useful noninvasive method for the demonstration of endocarditis and the associated valve ring abscess

  12. Deformation Differences between Tricuspid and Bicuspid Aortic Valves in Vitro

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    Szeto, Kai; Rodriguez-Rodriguez, Javier; Pastuszko, Peter; Nigam, Vishal; Lasheras, Juan C.

    2011-11-01

    It has been shown in clinical studies that patients with congenital bicuspid aortic valves (CBAVs) develop degenerative calcification of the leaflets at young ages compared to patients with the normal tricuspid aortic valves (TAVs). It has been hypothesized that the asymmetrical geometry of the leaflets in CBAVs, flow shear stresses (SS), disturbed flow, and excessive strain rate levels are possible causes for the early calcification and stenosis. Central to the validation of this hypothesis is the need to quantify the differences in strain rate levels between the BAVs and TAVs. We simulate the CBAVs by surgically stitching two of the leaflets of a porcine aortic valve together. To quantify strain differences, we performed in-vitro experiments in both trileaflet and bileaflet valves by tracking the motion of small ink dots marked on each leaflet surface. We then used phase-locked stereo photogrammetry to reconstruct at each instant of time the 3D surface of the leaflets and measure the strain rates in both radial and circumferential directions during the whole cardiac cycle. Our results indicate that the total strain rate of the simulated BAVs is about 15 to 20% higher than the normal leaflets of TAVs at systole. In the BAVs' case, the fused leaflet stretches radially up to 25% higher than the reference length. The excessive stretching in both directions in the fused leaflet results in large changes in the flow patterns and associated wall SS.

  13. Vascular Response of Ruthenium Tetraamines in Aortic Ring from Normotensive Rats

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    Ana Gabriela Conceição-Vertamatti

    2015-03-01

    Full Text Available Background: Ruthenium (Ru tetraamines are being increasingly used as nitric oxide (NO carriers. In this context, pharmacological studies have become highly relevant to better understand the mechanism of action involved. Objective: To evaluate the vascular response of the tetraamines trans-[RuII(NH34(Py(NO]3+, trans-[RuII(Cl(NO (cyclan](PF62, and trans-[RuII(NH34(4-acPy(NO]3+. Methods: Aortic rings were contracted with noradrenaline (10−6 M. After voltage stabilization, a single concentration (10−6 M of the compounds was added to the assay medium. The responses were recorded during 120 min. Vascular integrity was assessed functionally using acetylcholine at 10−6 M and sodium nitroprusside at 10−6 M as well as by histological examination. Results: Histological analysis confirmed the presence or absence of endothelial cells in those tissues. All tetraamine complexes altered the contractile response induced by norepinephrine, resulting in increased tone followed by relaxation. In rings with endothelium, the inhibition of endothelial NO caused a reduction of the contractile effect caused by pyridine NO. No significant responses were observed in rings with endothelium after treatment with cyclan NO. In contrast, in rings without endothelium, the inhibition of guanylate cyclase significantly reduced the contractile response caused by the pyridine NO and cyclan NO complexes, and both complexes caused a relaxing effect. Conclusion: The results indicate that the vascular effect of the evaluated complexes involved a decrease in the vascular tone induced by norepinephrine (10−6 M at the end of the incubation period in aortic rings with and without endothelium, indicating the slow release of NO from these complexes and suggesting that the ligands promoted chemical stability to the molecule. Moreover, we demonstrated that the association of Ru with NO is more stable when the ligands pyridine and cyclan are used in the formulation of the compound.

  14. Peroxynitrite-induced relaxation in isolated rat aortic rings and mechanisms of action

    International Nuclear Information System (INIS)

    Li Jianfeng; Li Wenyan; Altura, Bella T.; Altura, Burton M.

    2005-01-01

    The present study was designed to evaluate the effects of peroxynitrite (ONOO - ), the product of superoxide and nitric oxide, on isolated segments of rat aorta. In the absence of any vasoactive agent, ONOO - (from 10 -8 to 10 -4 M) failed to alter the basal tension. In phenylephrine (PE; 5 x 10 -7 M)-precontracted rat aortic rings (RAR), ONOO - elicited concentration-dependent relaxation at concentrations of from 10 -8 to 10 -4 M. The effective concentrations producing approximately 50% of maximal relaxation (ED 5 ) to ONOO - were 1.84 x 10 -5 M and 1.96 x 10 -5 M in intact and denuded RAR, respectively (P > 0.05). No significant differences in the relaxation responses were found between RAR with or without endothelium (P > 0.05). The presence of either 5 μM methylene blue (MB) or 5 μM 1H-[1,2,4]oxadiazolo-[4,3-α]quinoxalin-1-one (ODQ) significantly inhibited the relaxations induced by ONOO - . Sildenafil (10 -7 M), on the other hand, significantly potentiated the ONOO - -induced relaxations. Tetraethylammonium chloride (T-2265) significantly decreased the ONOO - -induced relaxations in a concentration-dependent manner. However, ONOO - had no effect on RAR precontracted by high KCL (40 mM, n = 6, P > 0.05). Addition of calyculin A also significantly decreased the ONOO - -induced relaxation in a dose-dependent manner. Furthermore, ONOO - significantly inhibited calcium-induced contractions of K + -depolarized aortic rings in a concentration-related manner. Lastly, a variety of other pharmacological agents and antagonists including L-NMMA, L-arginine, indomethacin, atropine, naloxone, diphenhydramine, cimetine, glibenclamide, haloperidol, superoxide dismutase (SOD), and catalase did not influence the relaxant effects of ONOO - on RAR. Our new results suggest that ONOO - -triggered relaxation on rat aortic rings is mediated by elevation of cGMP levels, membrane hyperpolarization via K + -channel activation, activation of myosin phosphatase activity, and

  15. Blueberry juice causes potent relaxation of rat aortic rings via the activation of potassium channels and the H₂S pathway.

    Science.gov (United States)

    Horrigan, Louise A; Holohan, Catherine A; Lawless, Gráinne A; Murtagh, Melissa A; Williams, Carmel T; Webster, Christina M

    2013-02-26

    The objective of this study was to investigate the in vitro effects of blueberry juice on healthy rat aortic rings, and to explore the roles of potassium channels and of the hydrogen sulphide (H(2)S) pathway in mediating the effects of blueberry juice. Firstly, the antioxidant capacity of blueberry juice was compared to other popular juice drinks using the Folin-Ciocalteu and the DPPH assays. Blueberry juice had significantly higher total polyphenol content than any of the other drinks studied (p blueberry juice on noradrenaline-contracted aortic rings was then observed, and the juice caused significant inhibition of noradrenaline-induced contractions (p blueberry juice (p blueberry juice (p blueberry juice has potent vasorelaxing properties, and thus may be a useful dietary agent for the prevention and treatment of hypertension. This study also provides strong evidence that Kv channels and the CSE/H(2)S pathway may be responsible, at least in part, for mediating the effects of blueberry juice.

  16. An in vitro experimental study of flow past aortic valve under varied pulsatile conditions

    Science.gov (United States)

    Zhang, Ruihang; Zhang, Yan

    2017-11-01

    Flow past aortic valve represents a complex fluid-structure interaction phenomenon that involves pulsatile, vortical, and turbulent conditions. The flow characteristics immediately downstream of the valve, such as the variation of pulsatile flow velocity, formation of vortices, distribution of shear stresses, are of particular interest to further elucidate the role of hemodynamics in various aortic diseases. However, the fluid dynamics of a realistic aortic valve is not fully understood. Particularly, it is unclear how the flow fields downstream of the aortic valve would change under varied pulsatile inlet boundary conditions. In this study, an in vitro experiment has been conducted to investigate the flow fields downstream of a silicone aortic valve model within a cardiovascular flow simulator. Phased-locked Particle Image Velocimetry measurements were performed to map the velocity fields and Reynolds normal and shear stresses at different phases in a cardiac cycle. Temporal variations of pressure across the valve model were measured using high frequency transducers. Results have been compared for different pulsatile inlet conditions, including varied frequencies (heart rates), magnitudes (stroke volumes), and cardiac contractile functions (shapes of waveforms).

  17. [Right-side aortic arch with aberrant left subclavian artery and Kommerell's diverticulum. A cause of vascular ring].

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    Tamayo-Espinosa, Tania; Erdmenger-Orellana, Julio; Becerra-Becerra, Rosario; Balderrabano-Saucedo, Norma; Segura-Standford, Begoña

    The right-side aortic arch may be associated with aberrant left subclavian artery, in some cases this artery originates from an aneurismal dilation of the aorta called Kommerell's diverticulum. A report is presented on 2 cases of vascular ring formed by a right-side aortic arch, anomalous left subclavian artery, Kommerell's diverticulum and left patent ductus arteriosus. A review the literature was also performed as regards the embryological development and the imaging methods used to help in the diagnosis of this rare vascular anomaly. Copyright © 2017 Instituto Nacional de Cardiología Ignacio Chávez. Publicado por Masson Doyma México S.A. All rights reserved.

  18. In vitro contraction of cytokinetic ring depends on myosin II but not on actin dynamics.

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    Mishra, Mithilesh; Kashiwazaki, Jun; Takagi, Tomoko; Srinivasan, Ramanujam; Huang, Yinyi; Balasubramanian, Mohan K; Mabuchi, Issei

    2013-07-01

    Cytokinesis in many eukaryotes involves the contraction of an actomyosin-based contractile ring. However, the detailed mechanism of contractile ring contraction is not fully understood. Here, we establish an experimental system to study contraction of the ring to completion in vitro. We show that the contractile ring of permeabilized fission yeast cells undergoes rapid contraction in an ATP- and myosin-II-dependent manner in the absence of other cytoplasmic constituents. Surprisingly, neither actin polymerization nor its disassembly is required for contraction of the contractile ring, although addition of exogenous actin-crosslinking proteins blocks ring contraction. Using contractile rings generated from fission yeast cytokinesis mutants, we show that not all proteins required for assembly of the ring are required for its contraction in vitro. Our work provides the beginnings of the definition of a minimal contraction-competent cytokinetic ring apparatus.

  19. Multidetector-row computed tomography of thoracic aortic anomalies in dogs and cats: Patent ductus arteriosus and vascular rings

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    Nolte Ingo

    2011-09-01

    Full Text Available Abstract Background Diagnosis of extracardiac intrathoracic vascular anomalies is of clinical importance, but remains challenging. Traditional imaging modalities, such as radiography, echocardiography, and angiography, are inherently limited by the difficulties of a 2-dimensional approach to a 3-dimensional object. We postulated that accurate characterization of malformations of the aorta would benefit from 3-dimensional assessment. Therefore, multidetector-row computed tomography (MDCT was chosen as a 3-dimensional, new, and noninvasive imaging technique. The purpose of this study was to evaluate patients with 2 common diseases of the intrathoracic aorta, either patent ductus arteriosus or vascular ring anomaly, by contrast-enhanced 64-row computed tomography. Results Electrocardiography (ECG-gated and thoracic nongated MDCT images were reviewed in identified cases of either a patent ductus arteriosus or vascular ring anomaly. Ductal size and morphology were determined in 6 dogs that underwent ECG-gated MDCT. Vascular ring anomalies were characterized in 7 dogs and 3 cats by ECG-gated MDCT or by a nongated thoracic standard protocol. Cardiac ECG-gated MDCT clearly displayed the morphology, length, and caliber of the patent ductus arteriosus in 6 affected dogs. Persistent right aortic arch was identified in 10 animals, 8 of which showed a coexisting aberrant left subclavian artery. A mild dilation of the proximal portion of the aberrant subclavian artery near its origin of the aorta was present in 4 dogs, and a diverticulum analogous to the human Kommerell's diverticulum was present in 2 cats. Conclusions Contrast-enhanced MDCT imaging of thoracic anomalies gives valuable information about the exact aortic arch configuration. Furthermore, MDCT was able to characterize the vascular branching patterns in dogs and cats with a persistent right aortic arch and the morphology and size of the patent ductus arteriosus in affected dogs. This additional

  20. Rosmarinic Acid Alleviates the Endothelial Dysfunction Induced by Hydrogen Peroxide in Rat Aortic Rings via Activation of AMPK

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    Hui Zhou

    2017-01-01

    Full Text Available Endothelial dysfunction is the key player in the development and progression of vascular events. Oxidative stress is involved in endothelial injury. Rosmarinic acid (RA is a natural polyphenol with antioxidative, antiapoptotic, and anti-inflammatory properties. The present study investigates the protective effect of RA on endothelial dysfunction induced by hydrogen peroxide (H2O2. Compared with endothelium-denuded aortic rings, the endothelium significantly alleviated the decrease of vasoconstrictive reactivity to PE and KCl induced by H2O2. H2O2 pretreatment significantly injured the vasodilative reactivity to ACh in endothelium-intact aortic rings in a concentration-dependent manner. RA individual pretreatment had no obvious effect on the vasoconstrictive reaction to PE and KCl, while its cotreatment obviously mitigated the endothelium-dependent relaxation impairments and the oxidative stress induced by H2O2. The RA cotreatment reversed the downregulation of AMPK and eNOS phosphorylation induced by H2O2 in HAEC cells. The pretreatment with the inhibitors of AMPK (compound C and eNOS (L-NAME wiped off RA’s beneficial effects. All these results demonstrated that RA attenuated the endothelial dysfunction induced by oxidative stress by activating the AMPK/eNOS pathway.

  1. In vitro characterization of bicuspid aortic valve hemodynamics using particle image velocimetry.

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    Saikrishnan, Neelakantan; Yap, Choon-Hwai; Milligan, Nicole C; Vasilyev, Nikolay V; Yoganathan, Ajit P

    2012-08-01

    The congenital bicuspid aortic valve (BAV) is associated with increased leaflet calcification, ascending aortic dilatation, aortic stenosis (AS) and regurgitation (AR). Although underlying genetic factors have been primarily implicated for these complications, the altered mechanical environment of BAVs could potentially accelerate these pathologies. The objective of the current study is to characterize BAV hemodynamics in an in vitro system. Two BAV models of varying stenosis and jet eccentricity and a trileaflet AV (TAV) were constructed from excised porcine AVs. Particle Image Velocimetry (PIV) experiments were conducted at physiological flow and pressure conditions to characterize fluid velocity fields in the aorta and sinus regions, and ensemble averaged Reynolds shear stress and 2D turbulent kinetic energy were calculated for all models. The dynamics of the BAV and TAV models matched the characteristics of these valves which are observed clinically. The eccentric and stenotic BAV showed the strongest systolic jet (V = 4.2 m/s), which impinged on the aortic wall on the non-fused leaflet side, causing a strong vortex in the non-fused leaflet sinus. The magnitudes of TKE and Reynolds stresses in both BAV models were almost twice as large as comparable values for TAV, and these maximum values were primarily concentrated around the central jet through the valve orifice. The in vitro model described here enables detailed characterization of BAV flow characteristics, which is currently challenging in clinical practice. This model can prove to be useful in studying the effects of altered BAV geometry on fluid dynamics in the valve and ascending aorta. These altered flows can be potentially linked to increased calcific responses from the valve endothelium in stenotic and eccentric BAVs, independent of concomitant genetic factors.

  2. In vitro flow investigations in the aortic arch during cardiopulmonary bypass with stereo-PIV.

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    Büsen, Martin; Kaufmann, Tim A S; Neidlin, Michael; Steinseifer, Ulrich; Sonntag, Simon J

    2015-07-16

    The cardiopulmonary bypass is related to complications like stroke or hypoxia. The cannula jet is suspected to be one reason for these complications, due to the sandblast effect on the vessel wall. Several in silico and in vitro studies investigated the underlying mechanisms, but the applied experimental flow measurement techniques were not able to address the highly three-dimensional flow character with a satisfying resolution. In this work in vitro flow measurements in a cannulated and a non-cannulated aortic silicone model are presented. Stereo particle image velocimetry measurements in multiple planes were carried out. By assembling the data of the different measurement planes, quasi 3D velocity fields with a resolution of~1.5×1.5×2.5 mm(3) were obtained. The resulting velocity fields have been compared regarding magnitude, streamlines and vorticity. The presented method shows to be a suitable in vitro technique to measure and address the three-dimensional aortic CPB cannula flow with a high temporal and spatial resolution. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. A new self-expandable aortic valved stent deployed above native leaflets for aortic insufficiency: an in vitro study.

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    Huang, H; Zhou, Y; Shao, J; Cai, J; Mei, Y; Wang, Y

    2012-12-01

    The aim of this paper was to develop a new self-expandable aortic valved stent following the shape of the sinus of Valsalva, which can be deployed above native leaflets for aortic regurgitation, and study it's effect on coronary artery flow when orthotopic implantation in and above native leaflets. New self-expandable aortic valved stent consist of nitinol stent and bovine pericardium, and was designed following the shape of the sinus of Valsalva, the bovine pericardium was tailed as native leaflet. Thirty-six swine hearts were divided into three equal groups of twelve. In Group A (N.=12), the new self-expandable aortic valved stents deployed in native leaflets. In Group B (N.=12), the new self-expandable aortic valved stents deployed above native leaflets. In Group C (N.=12), the cylinder-like valved stents deployed only in native leaflets. The measurements of each coronary flow rate and endoscopic inspections were repeated post-implantation. In Group A and C, valve implantation in native leaflets resulted in a significant decrease in both left and right coronary flows. In Group B, no significant change in either right or left coronary flow was found after new self-expandable aortic valved stent placement. Endoscopic inspections showed that in group A and C the native leaflets sandwiched between valved stent and aortic wall, whereas, in group B the native leaflets were under the artificial leaflets. Two kinds of stents deployed in native leaflets affect left and right coronary flows significantly. No significant effect was found when the new self-expandable aortic valved stent deployed above native leaflets. This new self-expandable aortic valved stent can be deployed above the native leaflets, which avoids the obstruction of native leaflets on coronary flow.

  4. Validation of a numerical FSI simulation of an aortic BMHV by in vitro PIV experiments.

    Science.gov (United States)

    Annerel, S; Claessens, T; Degroote, J; Segers, P; Vierendeels, J

    2014-08-01

    In this paper, a validation of a recently developed fluid-structure interaction (FSI) coupling algorithm to simulate numerically the dynamics of an aortic bileaflet mechanical heart valve (BMHV) is performed. This validation is done by comparing the numerical simulation results with in vitro experiments. For the in vitro experiments, the leaflet kinematics and flow fields are obtained via the particle image velocimetry (PIV) technique. Subsequently, the same case is numerically simulated by the coupling algorithm and the resulting leaflet kinematics and flow fields are obtained. Finally, the results are compared, revealing great similarity in leaflet motion and flow fields between the numerical simulation and the experimental test. Therefore, it is concluded that the developed algorithm is able to capture very accurately all the major leaflet kinematics and dynamics and can be used to study and optimize the design of BMHVs. Copyright © 2014 IPEM. Published by Elsevier Ltd. All rights reserved.

  5. A high-throughput in vitro ring assay for vasoactivity using magnetic 3D bioprinting

    Science.gov (United States)

    Tseng, Hubert; Gage, Jacob A.; Haisler, William L.; Neeley, Shane K.; Shen, Tsaiwei; Hebel, Chris; Barthlow, Herbert G.; Wagoner, Matthew; Souza, Glauco R.

    2016-01-01

    Vasoactive liabilities are typically assayed using wire myography, which is limited by its high cost and low throughput. To meet the demand for higher throughput in vitro alternatives, this study introduces a magnetic 3D bioprinting-based vasoactivity assay. The principle behind this assay is the magnetic printing of vascular smooth muscle cells into 3D rings that functionally represent blood vessel segments, whose contraction can be altered by vasodilators and vasoconstrictors. A cost-effective imaging modality employing a mobile device is used to capture contraction with high throughput. The goal of this study was to validate ring contraction as a measure of vasoactivity, using a small panel of known vasoactive drugs. In vitro responses of the rings matched outcomes predicted by in vivo pharmacology, and were supported by immunohistochemistry. Altogether, this ring assay robustly models vasoactivity, which could meet the need for higher throughput in vitro alternatives. PMID:27477945

  6. Multi-detector row computed tomographic evaluation of a rare type of complete vascular ring: Double aortic arch with atretic left arch distal to the origin of left subclavian artery

    Energy Technology Data Exchange (ETDEWEB)

    Hung, Ying Ying; Fu, Ching Yun; Wei, Hao Ji; Tsai, I Chen; Chen, Clayton Chi Chang [Taichung Veterans General Hospital, Taichung (China)

    2013-10-15

    Double aortic arch with an atretic left arch distal to the origin of left subclavian artery was diagnosed with multi-detector row computed tomography (MDCT) in two children with dysphagia. This rare type of complete vascular ring is clinically important because it may be confused with right aortic arch in mirror imaging. Anatomic details of this rare type of complete vascular ring demonstrated on MDCT facilitated appropriate surgical treatment.

  7. In-vitro analysis of early calcification in aortic valvular interstitial cells using Laser-Induced Breakdown Spectroscopy (LIBS).

    Science.gov (United States)

    Davari, Seyyed Ali; Masjedi, Shirin; Ferdous, Zannatul; Mukherjee, Dibyendu

    2018-01-01

    Calcific aortic valve disease (CAVD) is a major cardiovascular disorder caused by osteogenic differentiation of valvular interstitial cells (VICs) within aortic valves. Conventional methods like colorimetric assays and histology fail to detect small calcium depositions during in-vitro VIC cultures. Laser-induced breakdown spectroscopy (LIBS) is a robust analytical tool used for inorganic materials characterizations, but relatively new to biomedical applications. We employ LIBS, for the first time, for quantitative in-vitro detection of calcium depositions in VICs at various osteogenic differentiation stages. VICs isolated from porcine aortic valves were cultured in osteogenic media over various days. Colorimetric calcium assays based on arsenazo dye and Von Kossa staining measured the calcium depositions within VICs. Simultaneously, LIBS signatures for Ca I (422.67 nm) atomic emission lines were collected for estimating calcium depositions in lyophilized VIC samples. Our results indicate excellent linear correlation between the calcium assay and our LIBS measurements. Furthermore, unlike the assay results, the LIBS results could resolve calcium signals from cell samples with as early as 2 days of osteogenic culture. Quantitatively, the LIBS measurements establish the limit of detection for calcium content in VICs to be ∼0.17±0.04 μg which indicates a 5-fold improvement over calcium assay. Picture: Quantitative LIBS enables in-vitro analysis for early stage detection of calcium deposition within aortic valvular interstitial cells (VICs). © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Radial Force: An Underestimated Parameter in Oversizing Transcatheter Aortic Valve Replacement Prostheses: In Vitro Analysis with Five Commercialized Valves.

    Science.gov (United States)

    Egron, Sandrine; Fujita, Buntaro; Gullón, Lucía; Désirée, Pott; Schmitz-Rode, Thomas; Ensminger, Stephan; Steinseifer, Ulrich

    2017-09-05

    The goal is to inform in depth on transcatheter aortic valve replacement (TAVR) prosthesis mechanical behavior, depending on frame type, design, and size, and how it crucially impacts the oversizing issue in clinical use, and ultimately the procedure outcome. Transcatheter aortic valve replacement is an established therapy for high-risk patients suffering from aortic stenosis, and the indication for TAVR is progressively expanding to intermediate-risk patients. Choosing the optimal oversizing degree is crucial to safely anchor the TAVR valve-which involves limiting the risks for embolism, aortic regurgitation, conductance disturbance, or annulus rupture-and to increase the valve prosthesis performance. The radial force (RF) profiles of five TAVR prostheses were measured in vitro: the CoreValve 23 and 26 (Medtronic, MN), the Acurate neo S (Symetis, Switzerland), and the SAPIEN XT 23 and 26 (Edwards Lifesciences, CA). Measurements were run with the RX Machine equipment (Machine Solutions Inc., AZ), which is used in ISO standard tests for intravascular stents. Test protocols were adapted for TAVR prostheses. With the prostheses RF profiles' results, mechanical behavior differences could be described and discussed in terms of oversizing strategy and clinical impact for all five valves. Besides, crossing the prostheses' RF profiles with their recommended size windows made the assessment of borderline size cases possible and helped analyze the risks when accurate measurement of patient aortic annulus proves difficult. The prostheses' RF profiles bring new support in clinical decision-making for valve type and size in patients.

  9. Study of the effect of thiols on the vasodilatory potency of S-nitrosothiols by using a modified aortic ring assay

    International Nuclear Information System (INIS)

    Giustarini, Daniela; Tsikas, Dimitrios; Rossi, Ranieri

    2011-01-01

    Both low-molecular-mass thiols (LMM-SH) and protein thiols (P-SH) can modulate the biological activity of S-nitrosothiols (RSNO) via S-transnitrosation reactions. It has been difficult to evaluate the entity of this effect in blood circulation by in vitro assays with isolated aorta rings so far, because media rich in proteins cannot be used due to the foaming as a consequence of the needed gas bubbling. We have modified the original apparatus for organ bioassay in order to minimize foaming and to increase analytical performance. By using this modified bioassay we investigated the vasodilatory potency of various endogenous RSNOs in the presence of physiologically relevant concentrations of albumin and LMM-SH. Our results show that the sulfhydryl group of the cysteine moiety of albumin and LMM-SH has a dramatic effect on the vasodilatory potency of RSNO. Considering the equilibrium constants for S-transnitrosation reactions and the concentration of P-SH and LMM-SH we measured in healthy humans (aged 18-85 years), we infer that the age-dependency of hematic levels of LMM-SH may have a considerable impact in RSNO-mediated vasodilation. S-Nitrosoproteins such as S-nitrosoalbumin may constitute a relatively silent and constant amount of circulating RSNO. On the other hand, LMM-SH may mediate and control the biological actions of S-nitrosoproteins via S-transnitrosation reactions, by forming more potent nitric oxide-releasing LMM-S-nitrosothiols. Lifestyle habits, status of health and individual age are proven factors that, in turn, may influence the concentration of these compounds. These aspects should be taken into consideration when testing the vasodilatory effects of RSNO in pre-clinical studies. - Highlights: → A modification of the organ chamber apparatus for aortic ring bioassays is proposed. → The new apparatus can work in the presence of albumin at physiological concentrations. → Potency of RSNOs was studied in the presence of albumin and low molecular

  10. Tributyltin contributes in reducing the vascular reactivity to phenylephrine in isolated aortic rings from female rats.

    Science.gov (United States)

    Rodrigues, Samya Mere L; Ximenes, Carolina F; de Batista, Priscila R; Simões, Fabiana V; Coser, Pedro Henrique P; Sena, Gabriela C; Podratz, Priscila L; de Souza, Leticia N G; Vassallo, Dalton V; Graceli, Jones B; Stefanon, Ivanita

    2014-03-21

    Organotin compounds such as tributyltin (TBT) are used as antifouling paints by shipping companies. TBT inhibits the aromatase responsible for the transformation of testosterone into estrogen. Our hypothesis is that TBT modulates the vascular reactivity of female rats. Female Wistar rats were treated daily (Control; CONT) or TBT (100 ng/kg) for 15 days. Rings from thoracic aortas were incubated with phenylephrine (PHE, 10(-10)-10(-4) M) in the presence and absence of endothelium, and in the presence of N(G)-Nitro-L-Arginine Methyl Ester (L-NAME), tetraethylammonium (TEA) and apocynin. TBT decreased plasma levels of estrogen and the vascular response to PHE. In the TBT group, the vascular reactivity was increased in the absence of endothelium, L-NAME and TEA. The decrease in PHE reactivity during incubation with apocynin was more evident in the TBT group. The sensitivity to acetylcholine (ACh) and sodium nitroprusside (SNP) was reduced in the TBT group. TBT increased collagen, reduced α1-smooth muscle actin. Female rats treated with TBT for 15 days showed morphology alteration of the aorta and decreased their vascular reactivity, probably due to mechanisms dependent on nitric oxide (NO) bioavailability, K(+) channels and an increase in oxidative stress. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  11. Results of the in vitro ring trial:. Thorium and uranium isotopes in urine

    International Nuclear Information System (INIS)

    Hartmann, M.; Dalheimer, A.; Haenisch, K.

    2006-08-01

    On 22 September 2004 a workshop was held at the Berlin branch of the Federal Radiation Protection Office (BfS) on the in vitro ring trial ''Th isotopes and U isotopes in urine'' organised by the BfS head office for incorporation monitoring. The workshop was attended by 11 experts from the German, Austrian and Swiss incorporation measurement stations participating in the ring trial. The main focus of this second workshop was on the presentation of the results of the ring trial concerning Th and U isotopes in urine. According to paragraph 41 (8) of the Federal Radiation Protection Ordinance (StrlSchV 2001) one of the responsibilities of the head office for incorporation monitoring in terms of quality assurance is to have ring trials performed by the excretion analysis laboratories designated by the competent authorities as measurement stations. Section 5.2 of the Guideline on Requirements for Incorporation Monitoring Stations still in force (referred to in the following as the ''Requirements Guideline''/Guideline 1996) stipulates that incorporation measurement stations whose scope includes this type of measurement are obliged to participate in such ring trials. Inofficial and foreign incorporation measurement stations are also entitled to participate in ring trials organised by the head office. Ring trials may comprise either data acquisition or the dosimetric interpretation of data or both. By participating in ring trials measurement stations are supposed to demonstrate that the analysis and measurement methods they use are capable of supplying correct results with sufficient precision within the required time frame and of providing dosimetrically correct interpretations of activity increases

  12. Exercise training improves relaxation response and SOD-1 expression in aortic and mesenteric rings from high caloric diet-fed rats

    Directory of Open Access Journals (Sweden)

    Antunes Edson

    2008-05-01

    Full Text Available Abstract Background Obesity has been associated with a variety of disease such as type II diabetes mellitus, arterial hypertension and atherosclerosis. Evidences have shown that exercise training promotes beneficial effects on these disorders, but the underlying mechanisms are not fully understood. The aim of this study was to investigate whether physical preconditioning prevents the deleterious effect of high caloric diet in vascular reactivity of rat aortic and mesenteric rings. Methods Male Wistar rats were divided into sedentary (SD; trained (TR; sedentary diet (SDD and trained diet (TRD groups. Run training (RT was performed in sessions of 60 min, 5 days/week for 12 weeks (70–80% VO2max. Triglycerides, glucose, insulin and nitrite/nitrate concentrations (NOx- were measured. Concentration-response curves to acetylcholine (ACh and sodium nitroprusside (SNP were obtained. Expression of Cu/Zn superoxide dismutase (SOD-1 was assessed by Western blotting. Results High caloric diet increased triglycerides concentration (SDD: 216 ± 25 mg/dl and exercise training restored to the baseline value (TRD: 89 ± 9 mg/dl. Physical preconditioning significantly reduced insulin levels in both groups (TR: 0.54 ± 0.1 and TRD: 1.24 ± 0.3 ng/ml as compared to sedentary animals (SD: 0.87 ± 0.1 and SDD: 2.57 ± 0.3 ng/ml. On the other hand, glucose concentration was slightly increased by high caloric diet, and RT did not modify this parameter (SD: 126 ± 6; TR: 140 ± 8; SDD: 156 ± 8 and TRD 153 ± 9 mg/dl. Neither high caloric diet nor RT modified NOx- levels (SD: 27 ± 4; TR: 28 ± 6; SDD: 27 ± 3 and TRD: 30 ± 2 μM. Functional assays showed that high caloric diet impaired the relaxing response to ACh in mesenteric (about 13%, but not in aortic rings. RT improved the relaxing responses to ACh either in aortic (28%, for TR and 16%, to TRD groups or mesenteric rings (10%, for TR and 17%, to TRD groups that was accompanied by up-regulation of SOD-1

  13. Effect of Mucuna pruriens Seed Extract Pretreatment on the Responses of Spontaneously Beating Rat Atria and Aortic Ring to Naja sputatrix (Javan Spitting Cobra) Venom

    Science.gov (United States)

    Fung, Shin Yee; Tan, Nget Hong; Sim, Si Mui; Aguiyi, John C.

    2012-01-01

    Mucuna pruriens Linn. (velvet bean) has been used by native Nigerians as a prophylactic for snakebite. Rats pretreated with M. pruriens seed extract (MPE) have been shown to protect against the lethal and cardiovascular depressant effects of Naja sputatrix (Javan spitting cobra) venoms, and the protective effect involved immunological neutralization of the venom toxins. To investigate further the mechanism of the protective effect of MPE pretreatment against cobra venom toxicity, the actions of Naja sputatrix venom on spontaneously beating rat atria and aortic rings isolated from both MPE pretreated and untreated rats were studied. Our results showed that the MPE pretreatment conferred protection against cobra venom-induced depression of atrial contractility and atrial rate in the isolated atrial preparations, but it had no effect on the venom-induced contractile response of aortic ring preparation. These observations suggested that the protective effect of MPE pretreatment against cobra venom toxicity involves a direct protective action of MPE on the heart function, in addition to the known immunological neutralization mechanism, and that the protective effect does not involve action on blood vessel contraction. The results also suggest that M. pruriens seed may contain novel cardioprotective agent with potential therapeutic value. PMID:21785646

  14. Effect of Mucuna pruriens Seed Extract Pretreatment on the Responses of Spontaneously Beating Rat Atria and Aortic Ring to Naja sputatrix (Javan Spitting Cobra Venom

    Directory of Open Access Journals (Sweden)

    Shin Yee Fung

    2012-01-01

    Full Text Available Mucuna pruriens Linn. (velvet bean has been used by native Nigerians as a prophylactic for snakebite. Rats pretreated with M. pruriens seed extract (MPE have been shown to protect against the lethal and cardiovascular depressant effects of Naja sputatrix (Javan spitting cobra venoms, and the protective effect involved immunological neutralization of the venom toxins. To investigate further the mechanism of the protective effect of MPE pretreatment against cobra venom toxicity, the actions of Naja sputatrix venom on spontaneously beating rat atria and aortic rings isolated from both MPE pretreated and untreated rats were studied. Our results showed that the MPE pretreatment conferred protection against cobra venom-induced depression of atrial contractility and atrial rate in the isolated atrial preparations, but it had no effect on the venom-induced contractile response of aortic ring preparation. These observations suggested that the protective effect of MPE pretreatment against cobra venom toxicity involves a direct protective action of MPE on the heart function, in addition to the known immunological neutralization mechanism, and that the protective effect does not involve action on blood vessel contraction. The results also suggest that M. pruriens seed may contain novel cardioprotective agent with potential therapeutic value.

  15. Dicentric and ring chromosome yield in lymphocytes of in vitro irradiated blood of various donors

    International Nuclear Information System (INIS)

    Kubelka, D.; Horvat, D.; Svilicic, N.

    1988-01-01

    Results of in vitro irradiation of blood of nine human donors are presented. The blood irradiation doses were 0.1, 0.2, 0.5, 1, 2, and 3 Gy of X-ray exposure. The X-ray tube voltage was 250 kV. After irradiation, the standard 48-hours in vitro cultivation of lymphocytes was performed, with addition of BrdU, which enabled chromosome aberration analysis during the first in vitro division. Based on dicentric and ring yield, the dose-response curve has been generated for each donor. The tests on difference significance of obtained coefficients indicate there is no need for summary presentation of results. (author)

  16. Imidazolopiperazines (IPZ) kill both rings and dormant rings in wild type and K13 artemisinin resistant Plasmodium falciparum in vitro.

    Science.gov (United States)

    Dembele, Laurent; Gupta, Devendra Kumar; Lim, Michelle Yi-Xiu; Ang, Xiaoman; Selva, Jeremy J; Chotivanich, Kesinee; Nguon, Chea; Dondorp, Arjen M; Bonamy, Ghislain M C; Diagana, Thierry T; Bifani, Pablo

    2018-03-12

    Artemisinin (ART) resistance has spread through Southeast Asia, posing serious threat to the control and elimination of malaria. ART resistance has been associated with mutations in the Plasmodium falciparum kelch-13 ( Pfk13 ) propeller domain. Phenotypically, ART resistance is defined as delayed parasite clearance in patients' due to the reduced susceptibility of early ring-stage parasites to the active metabolite of ART dihydroartemisinin (DHA). Early rings can enter a state of quiescence upon DHA exposure and resume growth in its absence. These quiescent rings are referred to as dormant rings or DHA-pretreated rings (called here dormant rings). The imidazolopiperazine (IPZ) is a novel class of antimalarial drugs, which has demonstrated efficacy in early clinical trials. Here, we characterized the stage of action of IPZ GNF179 and evaluated its activity against rings and dormant rings in wild type and ART resistant parasites. Unlike DHA, GNF179 does not induce dormancy. We show that GNF179 is more rapidly cidal against schizonts than ring and trophozoite stages. However, with 12 hours exposure, the compound effectively kills rings and dormant rings of both susceptible and ART resistant parasites within 72 hours. We further demonstrate that in combination with ART, GNF179 effectively prevent recrudescence of dormant rings including those bearing pfk13 propeller mutations. Copyright © 2018 Dembele et al.

  17. Aortic arch malformations

    Energy Technology Data Exchange (ETDEWEB)

    Kellenberger, Christian J. [University Children' s Hospital, Department of Diagnostic Imaging, Zuerich (Switzerland)

    2010-06-15

    Although anomalies of the aortic arch and its branches are relatively uncommon malformations, they are often associated with congenital heart disease. Isolated lesions may be clinically significant when the airways are compromised by a vascular ring. In this article, the development and imaging appearance of the aortic arch system and its various malformations are reviewed. (orig.)

  18. Aortic arch malformations

    International Nuclear Information System (INIS)

    Kellenberger, Christian J.

    2010-01-01

    Although anomalies of the aortic arch and its branches are relatively uncommon malformations, they are often associated with congenital heart disease. Isolated lesions may be clinically significant when the airways are compromised by a vascular ring. In this article, the development and imaging appearance of the aortic arch system and its various malformations are reviewed. (orig.)

  19. Development of an In Vitro PIV Setup for Preliminary Investigation of the Effects of Aortic Compliance on Flow Patterns and Hemodynamics.

    Science.gov (United States)

    Büsen, Martin; Arenz, Christian; Neidlin, Michael; Liao, Sam; Schmitz-Rode, Thomas; Steinseifer, Ulrich; Sonntag, Simon J

    2017-09-01

    The aorta with its compliance plays a major role in hemodynamics as it saves a portion of ejected blood during systole which is then released in diastole. The aortic compliance decreases with increasing age, which is related to several cardiovascular imparities and diseases. Changes in flow patterns and pressure curves, due to varying aortic compliance, are difficult to investigate in vivo. As a result, the aim of the present work was to develop an in vitro setup enabling standardized investigations on the effect of compliance changes on flow patterns and pressure curves. Therefore an experimental setup with an anatomically correct silicone phantom of the aortic arch was developed, suitable for optical flow measurements under pulsatile inflow conditions. The setup was developed for precise adjustments of different compliances and optical flow measurements. Particle image velocimetry measurements were carried out downstream of the aortic valve in the center plane perpendicular to the valve with compliance adjusted between 0.62 × 10 -3 to 1.82 × 10 -3  mmHg -1 . Preliminary results of the in vitro investigations showed that decreases in compliance results in significant increases in pressure changes with respect to time (dp/dt) and altered pressure curves in the aortic arch. In terms of flow, an increased aortic stiffness lead to higher mean velocities and decreased vortex development in the aortic sinuses. As in vivo validation and translation remains difficult, the results have to be considered as preliminary in vitro insights into the mechanisms of (age-related) compliance changes.

  20. Persistent fifth arch anomalies - broadening the spectrum to include a variation of double aortic arch vascular ring

    Energy Technology Data Exchange (ETDEWEB)

    Newman, Beverley; Chan, Frandics [Stanford Children' s Hospital and Stanford University, Department of Radiology, Stanford, CA (United States); Hanneman, Kate [University of Toronto, Department of Medical Imaging, Toronto, ON (Canada)

    2016-12-15

    Fifth arch anomalies are rare and complex and frequently misdiagnosed or mistaken for other entities. We report a double arch vascular ring that is thought to consist of right fourth arch and left fifth arch components, a previously undescribed persistent fifth arch variant. The currently recognized spectrum and classification of fifth arch vascular anomalies are expanded along with illustrative images to justify the proposed changes. Reviewing and expanding the classification of fifth arch anomalies to include a double arch ring variant will promote recognition, correct diagnosis and appropriate management of these anomalies. (orig.)

  1. A ring test of a wireless in vitro gas production system

    DEFF Research Database (Denmark)

    Cornou, Cecile; Storm, Ida Marie Lindhardt Drejer; Hindrichsen, Ida Katarina Auf der M.

    2013-01-01

    ) or sheep (SP). Curves, corrected for blanks, were fitted using an exponential regression model with a lag time. The following variables were considered: (i) GP24 and GP48: raw values at 24 and 48 h (mL/g DM), corrected for blanks; (ii) A: asymptotic GP (mL/g DM); (iii) T1/2: time when half A is produced (h......); (iv) GPMR: maximum predicted GP rate (mL/h); (v) L: lag time (h). A mixed model including laboratories as random effect was used. A significant interaction between substrate and laboratories was found for all variables except A. The most repeatable and reproducible results were observed for A and GP48......The in vitro gas production (GP) technique has been widely used for feed evaluation. However, variability in results limits useful comparisons. Results from a ring test undertaken in four laboratories (Italy - IT, Spain - SP, Wales - WA and Denmark - DK) using the same wireless equipment (ANKOM...

  2. In vitro synthesis of biologically active transcripts of tomato black ring virus satellite RNA.

    Science.gov (United States)

    Greif, C; Hemmer, O; Demangeat, G; Fritsch, C

    1990-04-01

    Synthetic transcripts of tomato black ring virus satellite RNA (TBRV satRNA), isolate L, were prepared from cDNA cloned in the Bluescribe transcription vector. Transcripts with 49 (T49L) or two (T2GL) extra nucleotides at their 5' ends and 42 extra nucleotides at their 3' ends were able to induce, but to different extents, the synthesis in vitro of the satRNA-encoded 48K protein. However, when inoculated into Chenopodium quinoa together with TBRV L genomic RNAs, only T2GL was biologically active, in the presence or absence of a 5' cap analogue in the transcription reactions. Analysis of the 5' and 3' termini of the satRNA isolated from plants showed that nonviral extensions were not maintained in the transcript progeny.

  3. Green Synthesis of Silver Nanoparticles using Achillea biebersteinii Flower Extract and Its Anti-Angiogenic Properties in the Rat Aortic Ring Model

    Directory of Open Access Journals (Sweden)

    Javad Baharara

    2014-04-01

    Full Text Available Silver nanoparticles display unique physical and biological properties which have attracted intensive research interest because of their important medical applications. In this study silver nanoparticles (Ab.Ag-NPs were synthesized for biomedical applications using a completely green biosynthetic method using Achillea biebersteinii flowers extract. The structure and properties of Ab.Ag-NPs were investigated using UV-visible spectroscopic techniques, transmission electron microscopy (TEM, zeta potential and energy dispersive X-ray spectrometers (EDS. The UV-visible spectroscopic analysis showed the absorbance peak at 460 nm, which indicates the synthesis of silver nanoparticles. The average particle diameter as determined by TEM was found to be 12 ± 2 nm. The zeta potential analysis indicated that Ab.Ag-NPs have good stability EDX analysis also exhibits presentation of silver element. As angiogenesis is an important phenomenon and as growth factors imbalance in this process causes the acceleration of several diseases including cancer, the anti-angiogenic properties of Ab.Ag-NPs were evaluated using the rat aortic ring model. The results showed that Ab.Ag-NPs (200 μg/mL lead to a 50% reduction in the length and number of vessel-like structures. The synthesized silver nanoparticles from the Achillea biebersteinii flowers extract, which do not involve any harmful chemicals were well-dispersed and stabilized through this green method and showed potential therapeutic benefits against angiogenesis.

  4. P2Y purinoceptor and nucleotide receptor-induced relaxation of precontracted bovine aortic collateral artery rings: differential sensitivity to suramin and indomethacin.

    Science.gov (United States)

    Wilkinson, G F; McKechnie, K; Dainty, I A; Boarder, M R

    1994-02-01

    We have examined a series of adenine nucleotides and UTP for their ability to cause relaxation of precontracted bovine aortic collateral artery rings. The overall rank order of agonist potency for relaxation was 2-methylthioadenosine 5'-triphosphate (2MeSATP) > adenosine 5'-O-(3-thiotriphosphate) (ATP gamma S) > UTP > ADP > ATP. These responses were endothelium-dependent. Interaction studies showed that responses to the selective P2Y purinoceptor agonist 2MeSATP, and to ADP, were mediated by different receptors from those mediating responses to UTP. Suramin, a P2 purinoceptor antagonist that binds to diverse sites for ATP, produced a concentration-dependent shift in the agonist concentration-effect curve to 2MeSATP, with a pKB of 5.45 +/- 0.15 and a slope of 0.94 +/- 0.09. Suramin produced a small, nonsignificant shift in the UTP response curve and had little effect on responses to ATP. Indomethacin (2.8 x 10(-6) M) had no effect on concentration-effect curves to UTP but almost abolished the relaxations produced by 2MeSATP and ADP. The concentration-effect curves to ATP and ATP gamma S showed a significant (P effects of indomethacin show that these receptors differentially modulate the release of cyclooxygenase-derived mediators of relaxation.

  5. Stent fabric fatigue of grafts supported by Z-stents versus ringed stents: an in vitro buckling test.

    Science.gov (United States)

    Lin, Jing; Wang, Lu; Guidoin, Robert; Nutley, Mark; Song, Ge; Zhang, Ze; Du, Jia; Douville, Yvan

    2014-03-01

    Stent-grafts externally fitted with a Z-shaped stents were compared to devices fitted with ringed stents in an in vitro oscillating fatigue machine at 200 cycles per minute and a pressure of 360 mmHg for scheduled durations of up to 1 week. The devices fitted with Z-stents showed a considerably lower endurance limit to buckling compared to the controls. The contact between the apexes of adjacent Z-stents resulted in significant damage to the textile scaffolds and polyester fibers due to the sharp angle of the Z-stents. The ringed stents did not cause any fraying in the textile scaffolds.

  6. In vitro comparison of support capabilities of intra-aortic balloon pump and Impella 2.5 left percutaneous.

    Science.gov (United States)

    Schampaert, Stéphanie; van't Veer, Marcel; van de Vosse, Frans N; Pijls, Nico H J; de Mol, Bas A; Rutten, Marcel C M

    2011-09-01

    The Impella 2.5 left percutaneous (LP), a relatively new transvalvular assist device, challenges the position of the intra-aortic balloon pump (IABP), which has a long record in supporting patients after myocardial infarction and cardiac surgery. However, while more costly and more demanding in management, the advantages of the Impella 2.5 LP are yet to be established. The aim of this study was to evaluate the benefits of the 40 cc IABP and the Impella 2.5 LP operating at 47,000 rpm in vitro, and compare their circulatory support capabilities in terms of cardiac output, coronary flow, cardiac stroke work, and arterial blood pressure. Clinical scenarios of cardiogenic preshock and cardiogenic shock (CS), with blood pressure depression, lowered cardiac output, and constant heart rate of 80 bpm, were modeled in a model-controlled mock circulation, featuring a systemic, pulmonary, and coronary vascular bed. The ventricles, represented by servomotor-operated piston pumps, included the Frank-Starling mechanism. The systemic circulation was modeled with a flexible tube having close-to-human aortic dimensions and compliance properties. Proximally, it featured a branch mimicking the brachiocephalic arteries and a physiological correct coronary flow model. The rest of the systemic and pulmonary impedance was modeled by four-element Windkessel models. In this system, the enhancement of coronary flow and blood pressure was tested with both support systems under healthy and pathological conditions. Hemodynamic differences between the IABP and the Impella 2.5 LP were small. In our laboratory model, both systems approximately yielded a 10% cardiac output increase and a 10% coronary flow increase. However, since the Impella 2.5 LP provided significantly better left ventricular unloading, the circulatory support capabilities were slightly in favor of the Impella 2.5 LP. On the other hand, pulsatility was enhanced with the IABP and lowered with the Impella 2.5 LP. The support

  7. Inheritance of a Ring Chromosome 21 in a Couple Undergoing In Vitro Fertilization (IVF): A Case Report

    Science.gov (United States)

    Mazzaschi, Roberto L. P.; Love, Donald R.; Hayes, Ian; George, Alice

    2011-01-01

    An amniotic fluid sample from an in vitro fertilized pregnancy was referred for cytogenetic analysis based on a Down syndrome screening risk of 1 : 21. Routine cytogenetic analysis showed a nonmosaic karyotype of 46,XX,r(21)(p11.2q22.3), with partial monosomy for chromosome 21 due to a ring chromosome replacing one of the normal homologues. Detailed ultrasound scanning for the remainder of the pregnancy did not reveal any unusual findings. Parental bloods showed that the mother was mosaic for the ring 21 with a karyotype of 46,XX,r(21)(p11.2q22.3)/46,XX and the father had an unrelated Robertsonian translocation, with a karyotype of 45,XY,rob(13;14)(q10;q10). Microarray analysis of cultured amniocytes determined the extent of the deletion of chromosome 21 material in the ring. The parents were given genetic counselling, and a phenotypically normal female baby was delivered at term. This case highlights the importance of karyotyping as an initial step in the management of couples referred for in vitro fertilization. PMID:23074672

  8. Inheritance of a Ring Chromosome 21 in a Couple Undergoing In Vitro Fertilization (IVF: A Case Report

    Directory of Open Access Journals (Sweden)

    Roberto L. P. Mazzaschi

    2011-01-01

    Full Text Available An amniotic fluid sample from an in vitro fertilized pregnancy was referred for cytogenetic analysis based on a Down syndrome screening risk of 1 : 21. Routine cytogenetic analysis showed a nonmosaic karyotype of 46,XX,r(21(p11.2q22.3, with partial monosomy for chromosome 21 due to a ring chromosome replacing one of the normal homologues. Detailed ultrasound scanning for the remainder of the pregnancy did not reveal any unusual findings. Parental bloods showed that the mother was mosaic for the ring 21 with a karyotype of 46,XX,r(21(p11.2q22.3/46,XX and the father had an unrelated Robertsonian translocation, with a karyotype of 45,XY,rob(13;14(q10;q10. Microarray analysis of cultured amniocytes determined the extent of the deletion of chromosome 21 material in the ring. The parents were given genetic counselling, and a phenotypically normal female baby was delivered at term. This case highlights the importance of karyotyping as an initial step in the management of couples referred for in vitro fertilization.

  9. Shape and compliance of endothelial cells after shear stress in vitro or from different aortic regions: scanning ion conductance microscopy study.

    Directory of Open Access Journals (Sweden)

    Claire M F Potter

    Full Text Available To measure the elongation and compliance of endothelial cells subjected to different patterns of shear stress in vitro, and to compare these parameters with the elongation and compliance of endothelial cells from different regions of the intact aorta.Porcine aortic endothelial cells were cultured for 6 days under static conditions or on an orbital shaker. The shaker generated a wave of medium, inducing pulsatile shear stress with a preferred orientation at the edge of the well or steadier shear stress with changing orientation at its centre. The topography and compliance of these cells and cells from the inner and outer curvature of ex vivo porcine aortic arches were measured by scanning ion conductance microscopy (SICM.Cells cultured under oriented shear stress were more elongated and less compliant than cells grown under static conditions or under shear stress with no preferred orientation. Cells from the outer curvature of the aorta were more elongated and less compliant than cells from the inner curvature.The elongation and compliance of cultured endothelial cells vary according to the pattern of applied shear stress, and are inversely correlated. A similar inverse correlation occurs in the aortic arch, with variation between regions thought to experience different haemodynamic stresses.

  10. Aortic insufficiency

    Science.gov (United States)

    ... page, please enable JavaScript. Aortic insufficiency is a heart valve disease in which the aortic valve does not close ... aortic insufficiency Images Aortic insufficiency References Carabello BA. Valvular heart disease. In: Goldman L, Schafer AI, eds. Goldman-Cecil ...

  11. Analysis of the in vitro cleavage products of the tomato black ring virus RNA-1-encoded 250K polyprotein.

    Science.gov (United States)

    Demangeat, G; Greif, C; Hemmer, O; Fritsch, C

    1990-08-01

    Tomato black ring virus RNA-1 was translated in a rabbit reticulocyte lysate. The primary translation product of Mr 250K, which corresponds to its whole coding capacity, was synthesized within 45 min and, during further incubation in the translation medium, was proteolytically processed. Essentially, four cleavage products (P190, P120, P60 and P50) were detected and located within P250 by pulse-chase and immunoprecipitation experiments. P190 is an intermediate cleavage product which is further cleaved to form P60 and P120. P120, which contains the region that has been assigned to the virus protease and the virus polymerase, was not further cleaved in vitro.

  12. In vitro comparison of support capabilities of intra-aortic balloon pump and Impella 2.5 left percutaneous

    NARCIS (Netherlands)

    Schampaert, Stéphanie; van't Veer, Marcel; van de Vosse, Frans N.; Pijls, Nico H. J.; de Mol, Bas A.; Rutten, Marcel C. M.

    2011-01-01

    The Impella 2.5 left percutaneous (LP), a relatively new transvalvular assist device, challenges the position of the intra-aortic balloon pump (IABP), which has a long record in supporting patients after myocardial infarction and cardiac surgery. However, while more costly and more demanding in

  13. A ring test of in vitro neutral detergent fiber digestibility: Analytical variability and sample ranking

    Science.gov (United States)

    In vitro neutral detergent fiber (NDF) digestibility (NDFD) is an empirical measurement used to describe fermentability of NDF by rumen microbes. Variability is inherent in assays and affects the precision that can be expected for replicated samples. The study objective was to evaluate variability w...

  14. Reinforced aortic root reconstruction for acute type A aortic dissection involving the aortic root

    Directory of Open Access Journals (Sweden)

    Han Qing-qi

    2013-06-01

    Full Text Available OBJECTIVE: There are debates regarding the optimal approach for AAAD involving the aortic root. We described a modified reinforced aortic root reconstruction approach for treating AAAD involving the aortic root. METHODS: A total of 161 patients with AAAD involving the aortic root were treated by our modified reinforced aortic root reconstruction approach from January 1998 to December 2008. Key features of our modified approach were placement of an autologous pericardial patch in the false lumen, lining of the sinotubular junction lumen with a polyester vascular ring, and wrapping of the vessel with Teflon strips. Outcome measures included post-operative mortality, survival, complications, and level of aortic regurgitation. RESULTS: A total of 161 patients were included in the study (mean age: 43.3 1 15.5 years. The mean duration of follow-up was 5.1 1 2.96 years (2-12 years. A total of 10 (6.2% and 11 (6.8% patients died during hospitalization and during follow-up, respectively. Thirty-one (19.3% patients experienced postoperative complications. The 1-, 3-, 5-, and 10-year survival rates were 99.3%, 98%, 93.8%, and 75.5%, respectively. There were no instances of recurrent aortic dissection, aortic aneurysm, or pseudoaneurysm during the entire study period. The severity of aortic regurgitation dramatically decreased immediately after surgery (from 28.6% to 0% grade 3-4 and thereafter slightly increased (from 0% to 7.2% at 5 years and 9.1% at 10 years. CONCLUSION: This modified reinforced aortic root reconstruction was feasible, safe and durable/effective, as indicated by its low mortality, low postoperative complications and high survival rate.

  15. A ring test of in vitro neutral detergent fiber digestibility: analytical variability and sample ranking.

    Science.gov (United States)

    Hall, M B; Mertens, D R

    2012-04-01

    In vitro neutral detergent fiber (NDF) digestibility (NDFD) is an empirical measurement of fiber fermentability by rumen microbes. Variation is inherent in all assays and may be increased as multiple steps or differing procedures are used to assess an empirical measure. The main objective of this study was to evaluate variability within and among laboratories of 30-h NDFD values analyzed in repeated runs. Subsamples of alfalfa (n=4), corn forage (n=5), and grass (n=5) ground to pass a 6-mm screen passed a test for homogeneity. The 14 samples were sent to 10 laboratories on 3 occasions over 12 mo. Laboratories ground the samples and ran 1 to 3 replicates of each sample within fermentation run and analyzed 2 or 3 sets of samples. Laboratories used 1 of 2 NDFD procedures: 8 labs used procedures related to the 1970 Goering and Van Soest (GVS) procedure using fermentation vessels or filter bags, and 2 used a procedure with preincubated inoculum (PInc). Means and standard deviations (SD) of sample replicates within run within laboratory (lab) were evaluated with a statistical model that included lab, run within lab, sample, and lab × sample interaction as factors. All factors affected mean values for 30-h NDFD. The lab × sample effect suggests against a simple lab bias in mean values. The SD ranged from 0.49 to 3.37% NDFD and were influenced by lab and run within lab. The GVS procedure gave greater NDFD values than PInc, with an average difference across all samples of 17% NDFD. Because of the differences between GVS and PInc, we recommend using results in contexts appropriate to each procedure. The 95% probability limits for within-lab repeatability and among-lab reproducibility for GVS mean values were 10.2 and 13.4%, respectively. These percentages describe the span of the range around the mean into which 95% of analytical results for a sample fall for values generated within a lab and among labs. This degree of precision was supported in that the average maximum

  16. The in vitro protection of human decay accelerating factor and hDAF/heme oxygenase-1 transgenes in porcine aortic endothelial cells against sera of Formosan macaques.

    Science.gov (United States)

    Tu, C-F; Tai, H-C; Wu, C-P; Ho, L-L; Lin, Y-J; Hwang, C-S; Yang, T-S; Lee, J-M; Tseng, Y-L; Huang, C-C; Weng, C-N; Lee, P-H

    2010-01-01

    To mitigate hyperacute rejection, pigs have been generated with alpha-Gal transferase gene knockout and transgenic expression of human decay accelerating factor (hDAF), MCP, and CD59. Additionally, heme-oxygenase-1 (HO-1) has been suggested to defend endothelial cells. Sera (MS) (0%, 1%, 5%, 10%, and 15%) from Formosan macaques (Macaca cyclopis, MC), an Old World monkey wildly populated in Taiwan, was used to test the protective in vitro, effects of hDAF or hDAF/hHO-1 on porcine aortic endothelial cells (pAEC) derived from hDAF(+), hDAF(+)/hHO-1(+), and hDAF(+)/hHO-1(-) and 1 nontransgenic pAEC. Ten percent human serum (HS) served as a positive control. When MS addition increased to 10% or 15%, all transgenic pAEC exhibited a greater survival than nontransgenic pAEC. Noticeably, 15% MS reduced survived to 40% in nontransgenic and transgenic pAEC, respectively. These results revealed that hDAF exerted protective effects against MC complement activation. However, comparing with 10% MS and HS in pAEC of nontransgenic pigs, the survivability was higher in HS, suggesting that complement activation by MS was more toxic than that by HS. Furthermore, hDAF(+)/hHO-1(+) showed no further protection against effects of MS on transgenic pAEC. Copyright 2010 Elsevier Inc. All rights reserved.

  17. Aortic stenosis

    Science.gov (United States)

    ... Images Aortic stenosis Heart valves References Carabello BA. Valvular heart disease. In: Goldman L, Schafer AI, eds. Goldman-Cecil ... ACC guideline for the management of patients with valvular heart disease: a report of the American College of Cardiology/ ...

  18. Preoperative computer tomography evaluation in transcatheter aortic valve replacement (TAVI)

    International Nuclear Information System (INIS)

    Groudeva, V.; Stoynova, V.; Trendafilova, D.; Dzhorgova, Y.; Nachev, G.

    2014-01-01

    Transcatheter aortic valve replacement is rapidly emerging technique alternative to surgery in high risk patients. Imaging and especially computer tomography is important in preoperative assessment of the aortic ring and the prosthetic valve choice. The aim of this study is to share authors initial experience in CT assessment of the aortic ring prior to Transcatheter aortic valve replacement. 49 patients (mean age 76,55) underwent 320 rows MDCT (Acquilon One) prior TAVI. Protocol involved scanning from thoracic inlet to common femoral arteries. Aortic root size, aortic diameter at the level of coronary sinuses and the sinotubular junction and distance to coronary ostia were evaluated on a Vitrea work station. MDCT established maximal aortic ring diameter from 18 to 31 mm mean 25,04 mm while the lesser rate was from 16 to 21 mm. Accordingly positioned prostheses were in 34,75% No. 23, in 49% - No. 26 and in16,3% - No. 29. MDCT is crucial in aortic valve assessment prior to TAVI in experienced hands and multidisciplinary team. (authors) Key words: TRANSCATHETER AORTIC VALVE REPLACEMENT (TAVI). MDCT AORTIC VALVE ASSESSMENT

  19. Three-dimensional flow structures past a bio-prosthetic valve in an in-vitro model of the aortic root.

    Science.gov (United States)

    Hasler, David; Obrist, Dominik

    2018-01-01

    The flow field past a prosthetic aortic valve comprises many details that indicate whether the prosthesis is functioning well or not. It is, however, not yet fully understood how an optimal flow scenario would look, i.e. which subtleties of the fluid dynamics in place are essential regarding the durability and compatibility of a prosthetic valve. In this study, we measured and analyzed the 3D flow field in the vicinity of a bio-prosthetic heart valve in function of the aortic root size. The measurements were conducted within aortic root phantoms of different size, mounted in a custom-built hydraulic setup, which mimicked physiological flow conditions in the aorta. Tomographic particle image velocimetry was used to measure the 3D instantaneous velocity field at various instances. Several 3D fields (e.g. instantaneous and mean velocity, 3D shear rate) were analyzed and compared focusing on the impact of the aortic root size, but also in order to gain general insight in the 3D flow structure past the bio-prosthetic valve. We found that the diameter of the aortic jet relative to the diameter of the ascending aorta is the most important parameter in determining the characteristics of the flow. A large aortic cross-section, relative to the cross-section of the aortic jet, was associated with higher levels of turbulence intensity and higher retrograde flow in the ascending aorta.

  20. Comparative hepatic in vitro depletion and metabolite formation of major perfluorooctane sulfonate precursors in Arctic polar bear, beluga whale, and ringed seal.

    Science.gov (United States)

    Letcher, Robert J; Chu, Shaogang; McKinney, Melissa A; Tomy, Gregg T; Sonne, Christian; Dietz, Rune

    2014-10-01

    Perfluorooctane sulfonate (PFOS) has been reported to be among the most concentrated persistent organic pollutants in Arctic marine wildlife. The present study examined the in vitro depletion of major PFOS precursors, N-ethyl-perfluorooctane sulfonamide (N-EtFOSA) and perfluorooctane sulfonamide (FOSA), as well as metabolite formation using an assay based on enzymatically viable liver microsomes for three top Arctic marine mammalian predators, polar bear (Ursus maritimus), beluga whale (Delphinapterus leucas), and ringed seal (Pusa hispida), and in laboratory rat (Rattus rattus) serving as a general mammalian model and positive control. Rat assays showed that N-EtFOSA (38 nM or 150 ng mL(-1)) to FOSA metabolism was >90% complete after 10 min, and at a rate of 23 pmol min(-1) mg(-1) protein. Examining all species in a full 90 min incubation assay, there was >95% N-EtFOSA depletion for the rat active control and polar bear microsomes, ∼65% for ringed seals, and negligible depletion of N-EtFOSA for beluga whale. Concomitantly, the corresponding in vitro formation of FOSA from N-EtFOSA was also quantitatively rat≈polar bear>ringed seal>beluga whale. A lack of enzymatic ability and/or a rate too slow to be detected likely explains the lack of N-EtFOSA to FOSA transformation for beluga whale. In the same assays, the depletion of the FOSA metabolite was insignificant (p>0.01) and with no concomitant formation of PFOS metabolite. This suggests that, in part, a source of FOSA is the biotransformation of accumulated N-EtFOSA in free-ranging Arctic ringed seal and polar bear. Crown Copyright © 2014. Published by Elsevier Ltd. All rights reserved.

  1. Transcatheter aortic valve replacement

    Science.gov (United States)

    ... gov/ency/article/007684.htm Transcatheter aortic valve replacement To use the sharing features on this page, please enable JavaScript. Transcatheter aortic valve replacement (TAVR) is surgery to replace the aortic valve. ...

  2. Ring Theory

    CERN Document Server

    Jara, Pascual; Torrecillas, Blas

    1988-01-01

    The papers in this proceedings volume are selected research papers in different areas of ring theory, including graded rings, differential operator rings, K-theory of noetherian rings, torsion theory, regular rings, cohomology of algebras, local cohomology of noncommutative rings. The book will be important for mathematicians active in research in ring theory.

  3. Ampliación de anillo aórtico para implantación de prótesis: Evolución en el tiempo Aortic ring widening for prosthesis implantation: Evaluation throughout time

    Directory of Open Access Journals (Sweden)

    Oscar Velásquez

    2005-02-01

    Full Text Available Objetivo: describir las características cardíacas de pacientes sometidos a cambio valvular aórtico con ampliación del anillo para implantación de una prótesis mayor, mediante seguimiento clínico y ecocardiográfico. Materiales y métodos: entre 1997 y 2001 se tomaron 26 pacientes, de los cuales 13 (50%, con edad promedio de 57 años, se sometieron a seguimiento. La ecocardiografía se practicó en el control, obteniéndose área valvular aórtica, masa ventricular y gradientes transprotésicos para luego establecer los índices respectivos. Resultados: hubo mejoría en la clase funcional de los 13 pacientes controlados, con 92.3% en clase I (p= 0.002. La evolución postoperatoria fue de 25 meses en promedio. El índice de masa ventricular y los gradientes valvulares (medio presentaron reducción de 149 a 113 g/m2 y de 67 a 12.2 mm Hg respectivamente (p= 0.001; también se evidenció aumento en el índice de área efectiva valvular protésica que varió de 0.37 a 1 cm/m2 (p= 0.001. Discusión: los resultados evidencian involución en los trastornos ventriculares y mejoría en la clase funcional de los pacientes sometidos a este procedimiento; sin embargo, no se logró establecer comparación con pacientes que presentaran una prótesis menor a 21 mm de diámetro, lo que permitiría confirmar las ventajas de una válvula mayor. Conclusión: la cirugía de cambio valvular aórtico con ampliación del anillo para la implantación de una prótesis mayor, parece ser una alternativa para los pacientes con anillo aórtico nativo pequeño, evidenciándose mejoría clínica y ecocardiográfica en su evolución.Objective: to describe the cardiac characteristics of patients submitted to aortic valvular change with ring widening for a bigger prosthesis implantation, through clinical and echocardiographic follow-up. Material and methods: 26 patients were chosen between 1997 and 2001. Follow-up was possible in 13 patients. Mean age was 57 years. A

  4. Three-dimensional flow structures past a bio-prosthetic valve in an in-vitro model of the aortic root

    OpenAIRE

    Hasler, David; Obrist, Dominik

    2018-01-01

    The flow field past a prosthetic aortic valve comprises many details that indicate whether the prosthesis is functioning well or not. It is, however, not yet fully understood how an optimal flow scenario would look, i.e. which subtleties of the fluid dynamics in place are essential regarding the durability and compatibility of a prosthetic valve. In this study, we measured and analyzed the 3D flow field in the vicinity of a bio-prosthetic heart valve in function of the aortic root size. The m...

  5. Analysis of the in vitro cleavage products of the tomato black ring virus RNA-1-encoded 250K polyprotein.

    OpenAIRE

    Demangeat, Gerard; Greif, Charles; Hemmer, O; Fritsch, C

    1990-01-01

    Tomato black ring virus RNA-1 was translated in a rabbit reticulocyte lysate. The primary translation product of Mr 250K, which corresponds to its whole coding capacity, was synthesized within 45 min and, during further incubation in the translation medium, was proteolytically processed. Essentially, four cleavage products (P190, P120, P60 and P50) were detected and located within P250 by pulse-chase and immunoprecipitation experiments. P190 is an intermediate cleavage product which is furthe...

  6. Aortic valve bypass

    DEFF Research Database (Denmark)

    Lund, Jens T; Jensen, Maiken Brit; Arendrup, Henrik

    2013-01-01

    In aortic valve bypass (AVB) a valve-containing conduit is connecting the apex of the left ventricle to the descending aorta. Candidates are patients with symptomatic aortic valve stenosis rejected for conventional aortic valve replacement (AVR) or transcatheter aortic valve implantation (TAVI). ...

  7. In vitro processing of the RNA-2-encoded polyprotein of two nepoviruses: tomato black ring virus and grapevine chrome mosaic virus.

    Science.gov (United States)

    Demangeat, G; Hemmer, O; Fritsch, C; Le Gall, O; Candresse, T

    1991-02-01

    In vitro translation of RNA-2 of each of two closely related nepoviruses, tomato black ring virus (TBRV) and grapevine chrome mosaic virus (GCMV), in a rabbit reticulocyte lysate resulted in the synthesis of single polypeptides of 150K and 146K respectively. Processing of these polyproteins occurred after the addition of translation products of homologous RNA-1. The positions of the cleavage products within the polyproteins were determined. From the N to the C terminus, Mr values for the proteins were 50K, 46K and 59K for TBRV and 44K, 46K and 56K for GCMV. TBRV RNA-1 translation products also cleaved the polyproteins encoded by GCMV RNA-2 which suggests that the cleavage sites in the two polyproteins are similar.

  8. An in Vitro Twist Fatigue Test of Fabric Stent-Grafts Supported by Z-Stents vs. Ringed Stents

    Directory of Open Access Journals (Sweden)

    Jing Lin

    2016-02-01

    Full Text Available Whereas buckling can cause type III endoleaks, long-term twisting of a stent-graft was investigated here as a mechanism leading to type V endoleak or endotension. Two experimental device designs supported with Z-stents having strut angles of 35° or 45° were compared to a ringed control under accelerated twisting. Damage to each device was assessed and compared after different durations of twisting, with focus on damage that may allow leakage. Stent-grafts with 35° Z-stents had the most severe distortion and damage to the graft fabric. The 45° Z-stents caused less fabric damage. However, consistent stretching was still seen around the holes for sutures, which attach the stents to the graft fabric. Larger holes may become channels for fluid percolation through the wall. The ringed stent-graft had the least damage observed. Stent apexes with sharp angles appear to be responsible for major damage to the fabrics. Device manufacturers should consider stent apex angle when designing stent-grafts, and ensure their devices are resistant to twisting.

  9. An in Vitro Twist Fatigue Test of Fabric Stent-Grafts Supported by Z-Stents vs. Ringed Stents.

    Science.gov (United States)

    Lin, Jing; Guidoin, Robert; Du, Jia; Wang, Lu; Douglas, Graeham; Zhu, Danjie; Nutley, Mark; Perron, Lygia; Zhang, Ze; Douville, Yvan

    2016-02-16

    Whereas buckling can cause type III endoleaks, long-term twisting of a stent-graft was investigated here as a mechanism leading to type V endoleak or endotension. Two experimental device designs supported with Z-stents having strut angles of 35° or 45° were compared to a ringed control under accelerated twisting. Damage to each device was assessed and compared after different durations of twisting, with focus on damage that may allow leakage. Stent-grafts with 35° Z-stents had the most severe distortion and damage to the graft fabric. The 45° Z-stents caused less fabric damage. However, consistent stretching was still seen around the holes for sutures, which attach the stents to the graft fabric. Larger holes may become channels for fluid percolation through the wall. The ringed stent-graft had the least damage observed. Stent apexes with sharp angles appear to be responsible for major damage to the fabrics. Device manufacturers should consider stent apex angle when designing stent-grafts, and ensure their devices are resistant to twisting.

  10. Organophosphate esters in East Greenland polar bears and ringed seals: Adipose tissue concentrations and in vitro depletion and metabolite formation.

    Science.gov (United States)

    Strobel, Adelle; Willmore, William G; Sonne, Christian; Dietz, Rune; Letcher, Robert J

    2018-04-01

    East Greenland is a contamination "hot spot" for long-range transported anthropogenic chemicals, including organophosphate esters (OPEs). High concentrations of OPEs have been reported in arctic air while very little is known for wildlife where OPE tissue residues levels appear to be strongly influenced by biotransformation. In the present study, the hepatic in vitro metabolism of six environmentally relevant organophosphate (OP) triesters and corresponding OP diester formation were investigated in East Greenland polar bears (PBs) and ringed seals (RSs). The in vitro metabolism assay results were compared to adipose levels in field samples from the same individuals. In vitro OP triester metabolism was generally rapid and structure-dependent, where PBs metabolized OPEs more rapidly than RSs. Exceptions were the lack of triethyl phosphate (TEP) metabolism and slow metabolism of tris(2-ethylhexyl) phosphate (TEHP) in both species. OP diester metabolites were also formed with the exception of TEP which was not metabolized at all. Tris(1,3-dichloro-2-propyl) phosphate was completely converted to its corresponding diester. However, the mass balances showed that OP diester formation corresponding to TEHP, tri(n-butyl) phosphate, and tris(2-butyoxyethyl) phosphate did not account for 100% of the OP triester depletion, which indicated alternate pathways of OP triester metabolism had occurred. Triphenyl phosphate was completely converted to its OP diester metabolite in PBs but not in RSs suggesting species-specific differences. The results demonstrated that OP triester bioaccumulation and fate in PBs versus their RS prey is substantially influenced by biotransformation. Copyright © 2018 Elsevier Ltd. All rights reserved.

  11. A case of complete double aortic arch visualized by transthoracic echocardiography.

    Science.gov (United States)

    Saito, Naka; Kato, Shingo; Saito, Noritaka; Nakachi, Tatsuya; Fukui, Kazuki; Iwasawa, Tae; Kosuge, Masami; Kimura, Kazuo

    2017-08-01

    A case of double aortic arch that was well visualized using transthoracic echocardiography is reported. A 38-year-old man underwent transthoracic echocardiography for the evaluation of dyspnea. A suprasternal view of transthoracic echocardiography showed the ascending aorta bifurcate to left and right aortic arches, with blood flow from the ascending aorta to bilateral aortic arches. The diagnosis of right side-dominant double aortic arch was made, and the patient's symptom was conceivably related to compression of the trachea due to a vascular ring. This report indicates the potential usefulness of transthoracic echocardiography for noninvasive detection of double aortic arch in adults. © 2017, Wiley Periodicals, Inc.

  12. Aortic Annular Enlargement during Aortic Valve Replacement

    Directory of Open Access Journals (Sweden)

    Selman Dumani

    2016-09-01

    Full Text Available In the surgery of aortic valve replacement is always attempted, as much as possible, to implant the larger prosthesis with the mains goals to enhance the potential benefits, to minimise transvalvular gradient, decrease left ventricular size and avoid the phenomenon of patient-prosthesis mismatch. Implantation of an ideal prosthesis often it is not possible, due to a small aortic annulus. A variety of aortic annulus enlargement techniques is reported to avoid patient-prosthesis mismatch. We present the case that has submitted four three times open heart surgery. We used Manouguian technique to enlarge aortic anulus with excellent results during the fourth time of surgery.

  13. Aortic valve surgery - open

    Science.gov (United States)

    ... gov/ency/article/007408.htm Aortic valve surgery - open To use the sharing features on this page, ... separates the heart and aorta. The aortic valve opens so blood can flow out. It then closes ...

  14. Abdominal Aortic Aneurysm (AAA)

    Science.gov (United States)

    ... Professions Site Index A-Z Abdominal Aortic Aneurysm (AAA) Abdominal aortic aneurysm (AAA) occurs when atherosclerosis or plaque buildup causes the ... weak and bulge outward like a balloon. An AAA develops slowly over time and has few noticeable ...

  15. Inhibitory role of Notch1 in calcific aortic valve disease.

    Directory of Open Access Journals (Sweden)

    Asha Acharya

    Full Text Available Aortic valve calcification is the most common form of valvular heart disease, but the mechanisms of calcific aortic valve disease (CAVD are unknown. NOTCH1 mutations are associated with aortic valve malformations and adult-onset calcification in families with inherited disease. The Notch signaling pathway is critical for multiple cell differentiation processes, but its role in the development of CAVD is not well understood. The aim of this study was to investigate the molecular changes that occur with inhibition of Notch signaling in the aortic valve. Notch signaling pathway members are expressed in adult aortic valve cusps, and examination of diseased human aortic valves revealed decreased expression of NOTCH1 in areas of calcium deposition. To identify downstream mediators of Notch1, we examined gene expression changes that occur with chemical inhibition of Notch signaling in rat aortic valve interstitial cells (AVICs. We found significant downregulation of Sox9 along with several cartilage-specific genes that were direct targets of the transcription factor, Sox9. Loss of Sox9 expression has been published to be associated with aortic valve calcification. Utilizing an in vitro porcine aortic valve calcification model system, inhibition of Notch activity resulted in accelerated calcification while stimulation of Notch signaling attenuated the calcific process. Finally, the addition of Sox9 was able to prevent the calcification of porcine AVICs that occurs with Notch inhibition. In conclusion, loss of Notch signaling contributes to aortic valve calcification via a Sox9-dependent mechanism.

  16. The role of annular dimension and annuloplasty in tricuspid aortic valve repair.

    Science.gov (United States)

    de Kerchove, Laurent; Mastrobuoni, Stefano; Boodhwani, Munir; Astarci, Parla; Rubay, Jean; Poncelet, Alain; Vanoverschelde, Jean-Louis; Noirhomme, Philippe; El Khoury, Gebrine

    2016-02-01

    Valve sparing reimplantation can improve the durability of bicuspid aortic valve repair compared with subcommissural annuloplasty, especially in patients with a large basal ring. This study analyses the effect of basal ring size and annuloplasty on valve repair in the setting of a tricuspid aortic valve. From 1995 to 2013, 382 patients underwent elective tricuspid aortic valve repair. We included only those undergoing subcommissural annuloplasty, valve sparing reimplantation or no annuloplasty and in whom intraoperative transoesophageal echocardiography images were available for retrospective pre- and post-repair basal ring measurements (n = 323, subcommissural annuloplasty: 146, valve sparing reimplantation: 154, no annuloplasty: 23). In a subgroup of patients with available echocardiographic images, basal ring was retrospectively measured at the latest follow-up or prior to reoperation. subcommissural annuloplasty and valve sparing reimplantation were compared after matching for degree of aortic regurgitation and root size. All three groups differed significantly for most of preoperative characteristics. Hospital mortality was 0.9%. The median follow-up was 4.7 years. At 8 years, overall survival was 80 ± 5%. Freedom from reoperation and freedom from aortic regurgitation >1+ were 92 ± 5% and 71 ± 8%, respectively. In multivariate analysis, predictors of aortic regurgitation >1+ were left ventricular end-diastolic diameter (P = 0.003), cusp repair (P = 0.006), body surface area (P = 0.01) and subcommissural annuloplasty (P = 0.05). In subcommissural annuloplasty, freedom from aortic regurgitation >1+ was lower for patients with basal ring ≥28 mm compared with patients with basal ring 1+ was independent of basal ring size (P = 0.38). In matched comparison between subcommissural annuloplasty and valve sparing reimplantation, freedom from aortic regurgitation >1+ was not significantly different (P = 0.06), but in patients with basal ring ≥28 mm, valve sparing

  17. Black rings

    International Nuclear Information System (INIS)

    Emparan, Roberto; Reall, Harvey S

    2006-01-01

    A black ring is a five-dimensional black hole with an event horizon of topology S 1 x S 2 . We provide an introduction to the description of black rings in general relativity and string theory. Novel aspects of the presentation include a new approach to constructing black ring coordinates and a critical review of black ring microscopics. (topical review)

  18. White Ring; White ring

    Energy Technology Data Exchange (ETDEWEB)

    Aoki, H.; Yuzawa, H. [Nikken Sekkei Ltd., Osaka (Japan)

    1998-01-05

    White Ring is a citizen`s gymnasium used for figure skating and short track speed skating games of 18th Winter Olympic Games in 1998. White Ring is composed of a main-arena and a sub-arena. For the main-arena with an area 41mtimes66m, an ice link can be made by disengaging the potable floor and by flowing brine in the bridged polystyrene pipes embedded in the concrete floor. Due to the fortunate groundwater in this site, well water is used for the outside air treatment energy in 63% during heating and in 35% during cooling. Ammonia is used as a cooling medium for refrigerating facility. For the heating of audience area in the large space, heat load from the outside is reduced by enhancing the heat insulation performance of the roof of arena. The audience seats are locally heated using heaters. For the White Ring, high quality environment is realized for games through various functions of the large-scale roof of the large space. Success of the big event was expected. 15 figs., 4 tabs.

  19. Development of an in vitro Assay, based on the BioFilm Ring Test®, for Rapid Profiling of Biofilm-Growing Bacteria

    Directory of Open Access Journals (Sweden)

    Enea Gino Di Domenico

    2016-09-01

    Full Text Available Microbial biofilm represents a major virulence factor associated with chronic and recurrent infections. Pathogenic bacteria embedded in biofilms are highly resistant to environmental and chemical agents, including antibiotics and therefore difficult to eradicate. Thus, reliable tests to assess biofilm formation by bacterial strains as well as the impact of chemicals or antibiotics on biofilm formation represent desirable tools for a most effective therapeutic management and microbiological risk control. Current methods to evaluate biofilm formation are usually time-consuming, costly, and hardly applicable in the clinical setting.The aim of the present study was to develop and assess a simple and reliable in vitro procedure for the characterization of biofilm-producing bacterial strains for future clinical applications based on the BioFilm Ring Test® (BRT technology. The procedure developed for clinical testing (cBRT can provide an accurate and timely (5 hours measurement of biofilm formation for the most common pathogenic bacteria seen in clinical practice. The results gathered by the cBRT assay were in agreement with the traditional crystal violet (CV staining test, according to the kappa coefficient test (kappa = 0.623. However, the cBRT assay showed higher levels of specificity (92.2% and accuracy (88.1% as compared to CV. The results indicate that this procedure offers an easy, rapid and robust assay to test microbial biofilm and a promising tool for clinical microbiology.

  20. Efficient replication of the in vitro transcripts from cloned cDNA of tomato black ring virus satellite RNA requires the 48K satellite RNA-encoded protein.

    Science.gov (United States)

    Hemmer, O; Oncino, C; Fritsch, C

    1993-06-01

    Tomato black ring virus isolate L supports the multiplication of a large satellite RNA of 1376 nt which has no common features with the two genomic RNAs except for the terminal motif 5' VPg UUGAAAA and a 3' poly(A) tail. The TBRV sat-RNA contains an ORF for a protein of 48K which is translated both in vitro and in vivo. To determine the function of the 48K protein we have studied the effect of different mutations introduced in the ORF of the cDNA clone on the capacity of transcripts to multiply in Chenopodium quinoa plants or protoplasts when inoculated along with the genomic RNAs. Transcripts in which nucleotides have been substituted within the 5' proximal region of the ORF multiplied poorly even when the modification conserved the 48K protein sequence, suggesting that this portion of the ORF contains cis-acting RNA sequences. Transcripts with alterations in the internal region of the ORF retained their multiplication capacity provided the mutation did not destroy the ORF or modify the length of the protein expressed. The absence of multiplication in plants of transcripts unable to express the 48K protein and their inability to replicate in protoplasts suggest strongly that the sat-RNA translation product itself is implicated in the replication of sat-RNA.

  1. Systemic thioridazine in combination with dicloxacillin against early aortic graft infections caused by Staphylococcus aureus in a porcine model: In vivo results do not reproduce the in vitro synergistic activity.

    Directory of Open Access Journals (Sweden)

    Michael Stenger

    Full Text Available Conservative treatment solutions against aortic prosthetic vascular graft infection (APVGI for inoperable patients are limited. The combination of antibiotics with antibacterial helper compounds, such as the neuroleptic drug thioridazine (TDZ, should be explored.To investigate the efficacy of conservative systemic treatment with dicloxacillin (DCX in combination with TDZ (DCX+TDZ, compared to DCX alone, against early APVGI caused by methicillin-sensitive Staphylococcus aureus (MSSA in a porcine model.The synergism of DCX+TDZ against MSSA was initially assessed in vitro by viability assay. Thereafter, thirty-two pigs had polyester grafts implanted in the infrarenal aorta, followed by inoculation with 106 CFU of MSSA, and were randomly administered oral systemic treatment with either 1 DCX or 2 DCX+TDZ. Treatment was initiated one week postoperatively and continued for a further 21 days. Weight, temperature, and blood samples were collected at predefined intervals. By termination, bacterial quantities from the graft surface, graft material, and perigraft tissue were obtained.Despite in vitro synergism, the porcine experiment revealed no statistical differences for bacteriological endpoints between the two treatment groups, and none of the treatments eradicated the APVGI. Accordingly, the mixed model analyses of weight, temperature, and blood samples revealed no statistical differences.Conservative systemic treatment with DCX+TDZ did not reproduce in vitro results against APVGI caused by MSSA in this porcine model. However, unexpected severe adverse effects related to the planned dose of TDZ required a considerable reduction to the administered dose of TDZ, which may have compromised the results.

  2. Vortex rings

    CERN Document Server

    Akhmetov, D G

    2009-01-01

    This text on vortex rings covers their theoretical foundation, systematic investigations, and practical applications such as the extinction of fires at gushing oil wells. It pays special attention to the formation and motion of turbulent vortex rings.

  3. Towards real-time cardiovascular magnetic resonance-guided transarterial aortic valve implantation: In vitro evaluation and modification of existing devices

    Directory of Open Access Journals (Sweden)

    Ladd Mark E

    2010-10-01

    Full Text Available Abstract Background Cardiovascular magnetic resonance (CMR is considered an attractive alternative for guiding transarterial aortic valve implantation (TAVI featuring unlimited scan plane orientation and unsurpassed soft-tissue contrast with simultaneous device visualization. We sought to evaluate the CMR characteristics of both currently commercially available transcatheter heart valves (Edwards SAPIEN™, Medtronic CoreValve® including their dedicated delivery devices and of a custom-built, CMR-compatible delivery device for the Medtronic CoreValve® prosthesis as an initial step towards real-time CMR-guided TAVI. Methods The devices were systematically examined in phantom models on a 1.5-Tesla scanner using high-resolution T1-weighted 3D FLASH, real-time TrueFISP and flow-sensitive phase-contrast sequences. Images were analyzed for device visualization quality, device-related susceptibility artifacts, and radiofrequency signal shielding. Results CMR revealed major susceptibility artifacts for the two commercial delivery devices caused by considerable metal braiding and precluding in vivo application. The stainless steel-based Edwards SAPIEN™ prosthesis was also regarded not suitable for CMR-guided TAVI due to susceptibility artifacts exceeding the valve's dimensions and hindering an exact placement. In contrast, the nitinol-based Medtronic CoreValve® prosthesis was excellently visualized with delineation even of small details and, thus, regarded suitable for CMR-guided TAVI, particularly since reengineering of its delivery device toward CMR-compatibility resulted in artifact elimination and excellent visualization during catheter movement and valve deployment on real-time TrueFISP imaging. Reliable flow measurements could be performed for both stent-valves after deployment using phase-contrast sequences. Conclusions The present study shows that the Medtronic CoreValve® prosthesis is potentially suited for real-time CMR-guided placement

  4. Direct relationship between cell density and FDG uptake in asymptomatic aortic aneurysm close to surgical threshold: an in vivo and in vitro study

    Energy Technology Data Exchange (ETDEWEB)

    Marini, Cecilia [CNR Institute of Bioimaging and Molecular Physiology, Milan, Genoa Section, Genoa (Italy); Oftalmologia e Genetica dell' Universita di Genova, Dipartimento di Neuroscienze, Genoa (Italy); Morbelli, Silvia; Armonino, Riccardo; Riondato, Mattia; Massollo, Michela; Augeri, Carla; Fiz, Francesco; Sambuceti, Gianmario [University of Genoa, Department Internal Medicine, Chair of Nuclear Medicine, Genoa (Italy); Spinella, Giovanni; Pane, Bianca; Palmieri, Daniela; Palombo, Domenico [San Martino University Hospital, University of Genoa, Division of Vascular and Endovascular Surgery, Genoa (Italy); Sarocchi, Francesca; Abete, Luca; Fulcheri, Ezio [University of Genoa, Department of Surgical and Diagnostic Sciences, Pathology, Genoa (Italy); Ghigliotti, Giorgio [University of Genoa, Department of Internal Medicine, Chair of Cardiology, Genoa (Italy); Cittadini, Giuseppe [Hospital San Martino, Department of Radiology, Genoa (Italy)

    2012-01-15

    Conflicting results have been reported about the clinical value of fluorodeoxyglucose (FDG) imaging in predicting the risk of rupture of abdominal aortic aneurysm (AAA). The present study tests the hypothesis that FDG uptake is low in asymptomatic noninflammatory AAA due to the low cell density in aneurysmal walls. Positron emission tomography (PET)/CT imaging was performed in 12 consecutive candidates for AAA surgical repair and in 12 age- and sex-matched controls. At intervention, aneurysmal walls were cut into three sequential blocks. Block A was frozen to cut three 5-{mu}m slices for incubation with 2-3 MBq of FDG for 5 min. Block C was first incubated with the same tracer solution for the same time and subsequently frozen to cut three 5-{mu}m slices. Autoradiographic images were coregistered with immunohistochemical pictures of cell density, type and DNA synthesis as assessed on block B. No visible uptake in abdominal aorta occurred in any patient or control subject. Immunohistochemistry documented a severe loss of wall structure, with low numbers of cells. Tracer retention directly correlated with overall cell density and with prevalence of cells synthesizing DNA. The metabolic nature of FDG uptake was confirmed by the selective effect of preliminary freezing that decreased tracer content by 90% in regions with high cell density and only by 34% in cold acellular areas. The loss of tissue structure and the marked decrease in cell density account for the low prevalence of positive findings at FDG PET imaging, at least in asymptomatic patients bearing AAAs whose diameter is close to surgical indication. (orig.)

  5. Right cervical aortic arch with aberrant left subclavian artery.

    Science.gov (United States)

    Tjang, Yanto S; Aramendi, José I; Crespo, Alejandro; Hamzeh, Gadah; Voces, Roberto; Rodríguez, Miguel A

    2008-08-01

    The combination of right cervical aortic arch, aberrant retroesophageal left subclavian artery originating from a Kommerell's diverticulum, and a ligamentum arteriosum, constitutes a rare form of vascular ring. Two patients aged 21 days and 54 years, who were diagnosed by multislice 3-dimensional computed tomography and magnetic resonance imaging, underwent surgical division of a vascular ring. The adult required resection of a Kommerell's aneurysm and subclavian artery reimplantation.

  6. Abdominal aortic aneurysm neck remodeling after Anaconda stent graft implantation.

    Science.gov (United States)

    Vukovic, Elisabeth; Czerny, Martin; Beyersdorf, Friedhelm; Wolkewitz, Martin; Berezowski, Mikolaj; Siepe, Matthias; Blanke, Philipp; Rylski, Bartosz

    2018-05-24

    The aim of this study was to define how the proximal landing zone changes geometrically after endovascular abdominal aortic aneurysm repair (EVAR) with the Anaconda (Vascutek, Inchinnan, United Kingdom) stent graft. Among 230 patients who underwent Anaconda stent graft implantation between 2005 and 2014, we included 126 with adequate computed tomography (CT) image quality and follow-up. CT analysis entailed the geometric changes in the main body, proximal rings, and proximal landing zone. The median CT follow-up was 2.0 years (345.8 patients-years). The proximal portion of the main body ring system flattened within the first year after EVAR, resulting in an up to 30° increase in the upper ring's angle in 40% patients and up to 40° increase in 24% patients. One year after EVAR, the upper ring angle increase slowed down. Aortic diameter measured at the level of the upper and lower ring expanded by 2 to 4 mm within 1 year, but remained unchanged afterward. The main body migrated continuously down toward the aortic bifurcation, attaining an average 6-mm increase in the distance between the superior mesenteric artery and main body within 4 years. Freedom from endoleak type IA was 95 ± 2% and 93 ± 3% after 1 and 4 years, respectively. The Anaconda main body ring system in its proximal portion flattens within the first year after EVAR, leading to an increase of 2 to 4 mm in the proximal landing zone's aortic diameter. The main body migrates slowly but continuously down toward the aortic bifurcation. Copyright © 2018 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.

  7. Transcatheter Mitral Valve-in-Ring Implantation

    LENUS (Irish Health Repository)

    Tanner, RE

    2018-05-01

    Failed surgical mitral valve repair using an annuloplasty ring has traditionally been treated with surgical valve replacement or repair1. For patients at high risk for repeat open heart surgery, placement of a trans-catheter aortic valve (i.e., TAVI valve) within the mitral ring (i.e., Mitral-Valve-in-Ring, MViR) has emerged as a novel alternative treatment strategy2-5 . We describe our experience of a failed mitral valve repair that was successfully treated with a TAVI valve delivered via the trans-septal approach, and summarise the data relating to this emerging treatment strategy.

  8. Prosthetic valve sparing aortic root replacement: an improved technique.

    Science.gov (United States)

    Leacche, Marzia; Balaguer, Jorge M; Umakanthan, Ramanan; Byrne, John G

    2008-10-01

    We describe a modified surgical technique to treat patients with a previous history of isolated aortic valve replacement who now require aortic root replacement for an aneurysmal or dissected aorta. This technique consists of replacing the aortic root with a Dacron conduit, leaving intact the previously implanted prosthesis, and re-implanting the coronary arteries in the Dacron graft. Our technique differs from other techniques in that we do not leave behind any aortic tissue remnant and also in that we use a felt strip to obliterate any gap between the old sewing ring and the newly implanted graft. In our opinion, this promotes better hemostasis. We demonstrate that this technique is safe, feasible, and results in acceptable outcomes.

  9. Imaging in aortic dissection

    International Nuclear Information System (INIS)

    Yu-Qing Liu, M.D.

    1995-01-01

    Aortic dissection (AD) is a catastrophic aortic disease. Imaging techniques play an invaluable role in the diagnostic evaluation and management of patients with AD. Major signs of AD with different imaging modalities are described in this article with a pertinent discussion on guidelines for the optimized approach of imaging study (13 refs.)

  10. Imaging in aortic dissection

    Energy Technology Data Exchange (ETDEWEB)

    Yu-Qing Liu, M D [Chinese Academy of Medical Sciences, Beijing, BJ (China). Dept. of Radiology, Fu Wai Hospital and Cardiovascular Inst.

    1996-12-31

    Aortic dissection (AD) is a catastrophic aortic disease. Imaging techniques play an invaluable role in the diagnostic evaluation and management of patients with AD. Major signs of AD with different imaging modalities are described in this article with a pertinent discussion on guidelines for the optimized approach of imaging study (13 refs.).

  11. Recurrent Pneumonia due to Double Aortic Arch

    Directory of Open Access Journals (Sweden)

    I. Sedighi

    2012-04-01

    Full Text Available Introduction: Pneumonia is one of the most common infections during childhood. In children with recurrent bacterial pneumonia complete evaluation for underlying factors is necessary. The most common underlying diseases include: antibody deficiencies , cystic fibrosis , tracheoesophageal fistula and increased pulmonary blood flow. Vascular ring and its pressure effect is a less common cause of stridor and recurrent pneumonia. Congenital abnormalities in aortic arch and main branches which form vascular ring around esophagus and trachea with variable pressure effect cause respiratory symptoms such as stridor , wheezing and recurrent pneumoniaCase Report: A 2 year old boy was admitted in our hospital with respiratory distress and cough . Chest x-Ray demonstrated right lobar pneumonia. He had history of stridor and wheezing from neonatal period and hospitalization due to pneumonia for four times. The patient received appropriate antibiotics. Despite fever and respiratory distress improvement, wheezing continued. Review of his medical documents showed fixed pressure effect on posterior aspect of esophagus in barium swallow. In CT angiography we confirmed double aortic arch.Conclusion: Double aortic arch is one of the causes of persistant respiratory symptom and recurrent pneumonia in children for which fluoroscopic barium swallow is the first non-invasive diagnostic method.(Sci J Hamadan Univ Med Sci 2012;19(1:70-74

  12. Bovine aortic arch with supravalvular aortic stenosis.

    Science.gov (United States)

    Idhrees, Mohammed; Cherian, Vijay Thomas; Menon, Sabarinath; Mathew, Thomas; Dharan, Baiju S; Jayakumar, K

    2016-09-01

    A 5-year-old boy was diagnosed to have supravalvular aortic stenosis (SVAS). On evaluation of CT angiogram, there was associated bovine aortic arch (BAA). Association of BAA with SVAS has not been previously reported in literature, and to best of our knowledge, this is the first case report of SVAS with BAA. Recent studies show BAA as a marker for aortopathy. SVAS is also an arteriopathy. In light of this, SVAS can also possibly be a manifestation of aortopathy associated with BAA. Copyright © 2015 Cardiological Society of India. Published by Elsevier B.V. All rights reserved.

  13. Bovine aortic arch with supravalvular aortic stenosis

    Directory of Open Access Journals (Sweden)

    Mohammed Idhrees

    2016-09-01

    Full Text Available A 5-year-old boy was diagnosed to have supravalvular aortic stenosis (SVAS. On evaluation of CT angiogram, there was associated bovine aortic arch (BAA. Association of BAA with SVAS has not been previously reported in literature, and to best of our knowledge, this is the first case report of SVAS with BAA. Recent studies show BAA as a marker for aortopathy. SVAS is also an arteriopathy. In light of this, SVAS can also possibly be a manifestation of aortopathy associated with BAA.

  14. A geometric approach to aortic root surgical anatomy.

    Science.gov (United States)

    Contino, Monica; Mangini, Andrea; Lemma, Massimo Giovanni; Romagnoni, Claudia; Zerbi, Pietro; Gelpi, Guido; Antona, Carlo

    2016-01-01

    The aim of this study was the analysis of the geometrical relationships between the different structures constituting the aortic root, with particular attention to interleaflet triangles, haemodynamic ventriculo-arterial junction and functional aortic annulus in normal subjects. Sixteen formol-fixed human hearts with normal aortic roots were studied. The aortic root was isolated, sectioned at the midpoint of the non-coronary sinus, spread apart and photographed by a high-resolution digital camera. After calibration and picture resizing, the software AutoCAD 2004 was used to identify and measure all the elements of the interleaflets triangles and of the aortic root that were objects of our analysis. Multiple comparisons were performed with one-way analysis of variance for continuous data and with Kruskal-Wallis analysis for non-continuous data. Linear regression and Pearson's product correlation were used to correlate root element dimensions when appropriate. Student's t-test was used to compare means for unpaired data. Heron's formula was applied to estimate the functional aortic annular diameters. The non coronary-left coronary interleaflets triangles were larger, followed by inter-coronary and right-non-coronary ones. The apical angle is <60° and its standard deviation can be considered an asymmetry index. The sinu-tubular junction was shown to be 10% larger than the virtual basal ring (VBR). The mathematical relationship between the haemodynamic ventriculo-arterial junction and the VBR calculated by linear regression and expressed in terms of the diameter was: haemodynamic ventriculo-arterial junction = 2.29 VBR (diameter) + 47. Conservative aortic surgery is based on a better understanding of aortic root anatomy and physiology. The relationships among its elements are of paramount importance during aortic valve repair/sparing procedures and they can be useful also in echocardiographic analysis and in computed tomography reconstruction. © The Author 2015

  15. Migration into an in vitro experimental wound: a comparison of porcine aortic endothelial and smooth muscle cells and the effect of culture irradiation

    International Nuclear Information System (INIS)

    Gotlieb, A.I.; Spector, W.

    1981-01-01

    The purpose of this study was to compare the group-cell migration characteristics of endothelial cells (ECs) and smooth muscle cells (SMCs) derived from the same source, the porcine thoracic aorta, as they moved into an experimental in vitro wound. The authors characterized migration by measuring two aspects of the migrating cells: the number of free cells in the wound and the distance of migration of the sheet of cells at the wound edge. The quantitative data showed that ECs migrated into the wound as a sheet of cells, while SMCs migrated as free single cells. In addition, since irradiated cells have been used to study cell migration and since the irradiated cells do undergo some shape changes, the distribution of the cytoskeletal microfilament fibres was compared in migrating irradiated and nonirradiated cells in order to see whether this feature of cell migration was different. Irradiated and nonirradiated migrating ECs showed a strikingly different pattern in the orientation of microfilament bundles when studied by immunofluorescence microscopy with antiserums to myosin and tropomyosin

  16. Traumatic Aortic Injury

    Directory of Open Access Journals (Sweden)

    Brianna Miner

    2016-09-01

    Full Text Available History of present illness: A 48-year-old male with unknown past medical history presents as a trauma after being hit by a car traveling approximately 25 miles per hour. On initial presentation, the patient is confused, combative, and not answering questions appropriately. The patient is hypotensive with a blood pressure of 68/40 and a heart rate of 50 beats per minute, with oxygen saturation at 96% on room air. FAST scan is positive for fluid in Morrison’s pouch, splenorenal space, and pericardial space. Significant findings: The initial chest x-ray showed an abnormal superior mediastinal contour (blue line, suggestive of a possible aortic injury. The CT angiogram showed extensive circumferential irregularity and outpouching of the distal aortic arch (red arrows compatible with aortic transection. In addition, there was a circumferential intramural hematoma, which extended through the descending aorta to the proximal infrarenal abdominal aorta (green arrow. There was also an extensive surrounding mediastinal hematoma extending around the descending aorta and supraaortic branches (purple arrows. Discussion: Traumatic aortic injury is a life-threatening event. The incidence of blunt thoracic aortic injury is low, between 1 to 2 percent of those patients with blunt thoracic trauma.1 However, approximately 80% of patients with traumatic aortic injury die at the scene.2 Therefore it is imperative to diagnose traumatic aortic injury in a timely fashion. The diagnosis can be difficult due to the non-specific signs and symptoms and other distracting injuries. Clinical suspicion should be based on the mechanism of the injury and the hemodynamic status of the patient. In any patient with blunt or penetrating trauma to the chest that is hemodynamically unstable, traumatic aortic injury should be on the differential. Chest x-ray can be used as a screening tool. A normal chest x-ray has a negative predictive value of approximately 97%. CTA chest is the

  17. Association between osteopontin and human abdominal aortic aneurysm.

    Science.gov (United States)

    Golledge, Jonathan; Muller, Juanita; Shephard, Neil; Clancy, Paula; Smallwood, Linda; Moran, Corey; Dear, Anthony E; Palmer, Lyle J; Norman, Paul E

    2007-03-01

    In vitro and animal studies have implicated osteopontin (OPN) in the pathogenesis of aortic aneurysm. The relationship between serum concentration of OPN and variants of the OPN gene with human abdominal aortic aneurysm (AAA) was investigated. OPN genotypes were examined in 4227 subjects in which aortic diameter and clinical risk factors were measured. Serum OPN was measured by ELISA in two cohorts of 665 subjects. The concentration of serum OPN was independently associated with the presence of AAA. Odds ratios (and 95% confidence intervals) for upper compared with lower OPN tertiles in predicting presence of AAA were 2.23 (1.29 to 3.85, P=0.004) for the population cohort and 4.08 (1.67 to 10.00, P=0.002) for the referral cohort after adjusting for other risk factors. In 198 patients with complete follow-up of aortic diameter at 3 years, initial serum OPN predicted AAA growth after adjustment for other risk factors (standardized coefficient 0.24, P=0.001). The concentration of OPN in the aortic wall was greater in patients with small AAAs (30 to 50 mm) than those with aortic occlusive disease alone. There was no association between five single nucleotide polymorphisms or haplotypes of the OPN gene and aortic diameter or AAA expansion. Serum and tissue concentrations of OPN are associated with human AAA. We found no relationship between variation of the OPN gene and AAA. OPN may be a useful biomarker for AAA presence and growth.

  18. ring system

    African Journals Online (AJOL)

    1,3,2-DIAZABORACYCLOALKANE. RING SYSTEM. Negussie Retta" and Robert H. Neilson. 'Department of Chemistry, Addis Ababa University, P.O. Box 1176, Addis Ababa, Ethiopia. Department of Chemistry, Texas Christian University.

  19. Planetary Rings

    Science.gov (United States)

    Nicholson, P. D.

    2001-11-01

    A revolution in the studies in planetary rings studies occurred in the period 1977--1981, with the serendipitous discovery of the narrow, dark rings of Uranus, the first Voyager images of the tenuous jovian ring system, and the many spectacular images returned during the twin Voyager flybys of Saturn. In subsequent years, ground-based stellar occultations, HST observations, and the Voyager flybys of Uranus (1986) and Neptune (1989), as well as a handful of Galileo images, provided much additional information. Along with the completely unsuspected wealth of detail these observations revealed came an unwelcome problem: are the rings ancient or are we privileged to live at a special time in history? The answer to this still-vexing question may lie in the complex gravitational interactions recent studies have revealed between the rings and their retinues of attendant satellites. Among the four known ring systems, we see elegant examples of Lindblad and corotation resonances (first invoked in the context of galactic disks), electromagnetic resonances, spiral density waves and bending waves, narrow ringlets which exhibit internal modes due to collective instabilities, sharp-edged gaps maintained via tidal torques from embedded moonlets, and tenuous dust belts created by meteoroid impact onto parent bodies. Perhaps most puzzling is Saturn's multi-stranded, clumpy F ring, which continues to defy a simple explanation 20 years after it was first glimpsed in grainy images taken by Pioneer 11. Voyager and HST images reveal a complex, probably chaotic, dynamical interaction between unseen parent bodies within this ring and its two shepherd satellites, Pandora and Prometheus. The work described here reflects contributions by Joe Burns, Jeff Cuzzi, Luke Dones, Dick French, Peter Goldreich, Colleen McGhee, Carolyn Porco, Mark Showalter, and Bruno Sicardy, as well as those of the author. This research has been supported by NASA's Planetary Geology and Geophysics program and the

  20. Marginal accuracy of nickel chromium copings fabricated by conventional and accelerated casting procedures, produced with ringless and metal ring investment procedures: A comparative in vitro study

    Directory of Open Access Journals (Sweden)

    Deepa Alex

    2015-01-01

    Conclusion: The Ni-Cr cast copings fabricated with the conventional casting using ringless investment system showed significantly better marginal fit than that of cast copings fabricated from conventional and accelerated casting with metal ring investment and accelerated casting using ringless investment since those copings had shown the least vertical marginal discrepancies among the four methods evaluated in this study.

  1. Marginal accuracy of nickel chromium copings fabricated by conventional and accelerated casting procedures, produced with ringless and metal ring investment procedures: A comparative in vitro study

    Science.gov (United States)

    Alex, Deepa; Shetty, Y. Bharath; Miranda, Glynis Anita; Prabhu, M. Bharath; Karkera, Reshma

    2015-01-01

    Background: Conventional investing and casting techniques are time-consuming and usually requires 2–4 h for completion. Accelerated nonstandard, casting techniques have been reported to achieve similar quality results in significantly less time, namely, in 30–40 min. During casting, it is essential to achieve compensation for the shrinkage of solidifying alloy by investment expansion. The metal casting ring restricts the thermal expansion of investment because the thermal expansion of the ring is lesser than that of the investment. The use of casting ring was challenged with the introduction of the ringless technique. Materials and Methods: A total of 40 test samples of nickel chromium (Ni-Cr) cast copings were obtained from the patterns fabricated using inlay casting wax. The 20 wax patterns were invested using metal ring and 20 wax patterns were invested using the ringless investment system. Of both the groups, 10 samples underwent conventional casting, and the other 10 underwent accelerated casting. The patterns were casted using the induction casting technique. All the test samples of cast copings were evaluated for vertical marginal gaps at four points on the die employing a stereo optical microscope. Results: The vertical marginal discrepancy data obtained were tabulated. Mean and standard deviations were obtained. Vertical discrepancies were analyzed using analysis of variance and Tukey honestly significantly different. The data obtained were found to be very highly significant (P marginal fit than that of cast copings fabricated from conventional and accelerated casting with metal ring investment and accelerated casting using ringless investment since those copings had shown the least vertical marginal discrepancies among the four methods evaluated in this study. PMID:26929488

  2. Marginal accuracy of nickel chromium copings fabricated by conventional and accelerated casting procedures, produced with ringless and metal ring investment procedures: A comparative in vitro study.

    Science.gov (United States)

    Alex, Deepa; Shetty, Y Bharath; Miranda, Glynis Anita; Prabhu, M Bharath; Karkera, Reshma

    2015-01-01

    Conventional investing and casting techniques are time-consuming and usually requires 2-4 h for completion. Accelerated nonstandard, casting techniques have been reported to achieve similar quality results in significantly less time, namely, in 30-40 min. During casting, it is essential to achieve compensation for the shrinkage of solidifying alloy by investment expansion. The metal casting ring restricts the thermal expansion of investment because the thermal expansion of the ring is lesser than that of the investment. The use of casting ring was challenged with the introduction of the ringless technique. A total of 40 test samples of nickel chromium (Ni-Cr) cast copings were obtained from the patterns fabricated using inlay casting wax. The 20 wax patterns were invested using metal ring and 20 wax patterns were invested using the ringless investment system. Of both the groups, 10 samples underwent conventional casting, and the other 10 underwent accelerated casting. The patterns were casted using the induction casting technique. All the test samples of cast copings were evaluated for vertical marginal gaps at four points on the die employing a stereo optical microscope. The vertical marginal discrepancy data obtained were tabulated. Mean and standard deviations were obtained. Vertical discrepancies were analyzed using analysis of variance and Tukey honestly significantly different. The data obtained were found to be very highly significant (P cast copings fabricated with the conventional casting using ringless investment system showed significantly better marginal fit than that of cast copings fabricated from conventional and accelerated casting with metal ring investment and accelerated casting using ringless investment since those copings had shown the least vertical marginal discrepancies among the four methods evaluated in this study.

  3. Aortic valve replacement for aortic stenosis caused by alkaptonuria.

    Science.gov (United States)

    Hiroyoshi, Junko; Saito, Aya; Panthee, Nirmal; Imai, Yasushi; Kawashima, Dai; Motomura, Noboru; Ono, Minoru

    2013-03-01

    We report a case of aortic stenosis associated with ochronosis in a 70-year-old man who underwent biologic aortic valve replacement. Intraoperative findings included ochronosis of a severely calcified pigmented aortic valve along with pigmentation of the intima of the aorta. Copyright © 2013 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

  4. Storage Rings

    International Nuclear Information System (INIS)

    Fischer, W.

    2010-01-01

    Storage rings are circular machines that store particle beams at a constant energy. Beams are stored in rings without acceleration for a number of reasons (Tab. 1). Storage rings are used in high-energy, nuclear, atomic, and molecular physics, as well as for experiments in chemistry, material and life sciences. Parameters for storage rings such as particle species, energy, beam intensity, beam size, and store time vary widely depending on the application. The beam must be injected into a storage ring but may not be extracted (Fig. 1). Accelerator rings such as synchrotrons are used as storage rings before and after acceleration. Particles stored in rings include electrons and positrons; muons; protons and anti-protons; neutrons; light and heavy, positive and negative, atomic ions of various charge states; molecular and cluster ions, and neutral polar molecules. Spin polarized beams of electrons, positrons, and protons were stored. The kinetic energy of the stored particles ranges from 10 -6 eV to 3.5 x 10 12 eV (LHC, 7 x 10 12 eV planned), the number of stored particles from one (ESR) to 1015 (ISR). To store beam in rings requires bending (dipoles) and transverse focusing (quadrupoles). Higher order multipoles are used to correct chromatic aberrations, to suppress instabilities, and to compensate for nonlinear field errors of dipoles and quadrupoles. Magnetic multipole functions can be combined in magnets. Beams are stored bunched with radio frequency systems, and unbunched. The magnetic lattice and radio frequency system are designed to ensure the stability of transverse and longitudinal motion. New technologies allow for better storage rings. With strong focusing the beam pipe dimensions became much smaller than previously possible. For a given circumference superconducting magnets make higher energies possible, and superconducting radio frequency systems allow for efficient replenishment of synchrotron radiation losses of large current electron or positron beams

  5. Pathogenetic Basis of Aortopathy and Aortic Valve Disease

    Science.gov (United States)

    2018-02-19

    Aortopathies; Thoracic Aortic Aneurysm; Aortic Valve Disease; Thoracic Aortic Disease; Thoracic Aortic Dissection; Thoracic Aortic Rupture; Ascending Aortic Disease; Descending Aortic Disease; Ascending Aortic Aneurysm; Descending Aortic Aneurysm; Marfan Syndrome; Loeys-Dietz Syndrome; Ehlers-Danlos Syndrome; Shprintzen-Goldberg Syndrome; Turner Syndrome; PHACE Syndrome; Autosomal Recessive Cutis Laxa; Congenital Contractural Arachnodactyly; Arterial Tortuosity Syndrome

  6. Topological rings

    CERN Document Server

    Warner, S

    1993-01-01

    This text brings the reader to the frontiers of current research in topological rings. The exercises illustrate many results and theorems while a comprehensive bibliography is also included. The book is aimed at those readers acquainted with some very basic point-set topology and algebra, as normally presented in semester courses at the beginning graduate level or even at the advanced undergraduate level. Familiarity with Hausdorff, metric, compact and locally compact spaces and basic properties of continuous functions, also with groups, rings, fields, vector spaces and modules, and with Zorn''s Lemma, is also expected.

  7. Ring accelerators

    International Nuclear Information System (INIS)

    Gisler, G.; Faehl, R.

    1983-01-01

    We present two-dimensional simulations in (r-z) and r-theta) cylinderical geometries of imploding-liner-driven accelerators of rings of charged particles. We address issues of azimuthal and longitudinal stability of the rings. We discuss self-trapping designs in which beam injection and extraction is aided by means of external cusp fields. Our simulations are done with the 2-1/2-D particle-in-cell plasma simulation code CLINER, which combines collisionless, electromagnetic PIC capabilities with a quasi-MHD finite element package

  8. Robotic aortic surgery.

    Science.gov (United States)

    Duran, Cassidy; Kashef, Elika; El-Sayed, Hosam F; Bismuth, Jean

    2011-01-01

    Surgical robotics was first utilized to facilitate neurosurgical biopsies in 1985, and it has since found application in orthopedics, urology, gynecology, and cardiothoracic, general, and vascular surgery. Surgical assistance systems provide intelligent, versatile tools that augment the physician's ability to treat patients by eliminating hand tremor and enabling dexterous operation inside the patient's body. Surgical robotics systems have enabled surgeons to treat otherwise untreatable conditions while also reducing morbidity and error rates, shortening operative times, reducing radiation exposure, and improving overall workflow. These capabilities have begun to be realized in two important realms of aortic vascular surgery, namely, flexible robotics for exclusion of complex aortic aneurysms using branched endografts, and robot-assisted laparoscopic aortic surgery for occlusive and aneurysmal disease.

  9. Postmortem computed tomographic (PMCT) findings of pericardial effusion due to acute aortic dissection

    International Nuclear Information System (INIS)

    Shiotani, Seiji; Watanabe, Ko; Kohno, Mototsugu; Ohashi, Noriyoshi; Nakayama, Hidetsugu; Yamazaki, Kentaro

    2004-01-01

    The purpose of this study was to describe the appearance of pericardial effusion in deceased acute aortic dissection patients using postmortem computed tomography (PMCT). PMCT examinations were performed within 2 hours of death in 30 patients with pericardial effusion due to aortic dissection who arrived at our hospital in a state of cardiopulmonary arrest. Pericardial effusion in 18 of 30 patients (60%) showed double concentric rings on PMCT with striking differences in density, a low-density outer ring along the pericardium and a high-density inner ring on the epicardial surface (hyperdense armored heart). Pericardial effusion in two patients (7%) showed a high-density fluid level (hypostasis). Pericardial effusion in the remaining 10 patients (33%) showed no such stratification. A ''hyperdense armored heart'' is the most frequently seen PMCT finding in deceased cases of pericardial effusion due to acute aortic dissection. (author)

  10. Ring interferometry

    CERN Document Server

    Malykin, Grigorii B; Zhurov, Alexei

    2013-01-01

    This monograph is devoted to the creation of a comprehensive formalism for quantitative description of polarized modes' linear interaction in modern single-mode optic fibers. The theory of random connections between polarized modes, developed in the monograph, allows calculations of the zero shift deviations for a fiber ring interferometer. The monograph addresses also the

  11. Aortic valve replacement

    DEFF Research Database (Denmark)

    Kapetanakis, Emmanouil I; Athanasiou, Thanos; Mestres, Carlos A

    2008-01-01

    mortality were collected. Group analysis by patient geographic distribution and by annular diameter of the prosthesis utilized was conducted. Patients with a manufacturer's labeled prosthesis size > or = 21 mm were assigned to the 'large' aortic size subset, while those with a prosthesis size ... differences in the distribution of either gender or BSA. In the multivariable model, south European patients were seven times more likely to receive a smaller-sized aortic valve (OR = 6.5, 95% CI = 4.82-8.83, p

  12. Postoperative CT findings of aortic aneurysm and dissection

    International Nuclear Information System (INIS)

    Seong, Su Ok; Lee, Ghi Jai; Kim, Mi Young; Moon, Hi Eun; Shim, Jae Chan; Lee, Hong Sup; Kim, Ho Kyun; Han, Chang Yul

    1995-01-01

    To assess the postoperative CT findings of aortic aneurysms or dissections treared by resection-and graft replacement or continuous-suture graft-inclusion technique. We reviewed postoperative follow-up CT findings of 14 patients, 19 cases. There were 8 patients (10 cases) of aortic aneurysm and 6 patients (9 cases) of aortic dissection which involved the thoracic aorta in 9 patients (13 cases) and abdominal aorta in 5 patients (6 cases). The interval of follow-up after operation was from 9 days to 2 year 9 months. On CT scans, we analyzed the appearance of graft materials, differences of CT findings between two surgical techniques, and normal or abnormal postoperative CT findings. Most of grafts appeared as hyperdense ring on precontrast scan, and all of them were not separated from aortic lumen on postcontrast scan. On CT findings of patients who were operated by continuous-suture graft-inclusion technique, perigraft thrombus was concentrically located with sharp demarcation by native aortic wall and its density was homogeneous, but in cases of those operated by resection-and graft replacement, perigraft hematoma was eccentrically located with indistinct margin and its density was heterogeneous and native aortic wall could not be delineated. In patients without complication, perigraft thrombus or hematoma (15 cases), perigraft calcification (11 cases), residual intimal flap (6 cases), graft deformity (4 cases), perigraft air (2 cases) and reconstructed vessels (1 cases) were noted. And in one patient with complication, perigraft flow was noted with more increased perigraft hematoma. Precise knowledge of the differences of CT findings between two surgical techniques and normal postoperative CT findings is crucial to evaluated the postoperative CT findings in aortic aneurysm and dissection

  13. Double aortic arch

    Science.gov (United States)

    Surgery can be done to fix double aortic arch. The surgeon ties off the smaller branch and separates it from the larger branch. Then the surgeon closes the ends of the aorta with stitches. This relieves pressure on the esophagus and windpipe.

  14. Bicuspid aortic valve

    Science.gov (United States)

    ... aortic disease. In: Otto CM, Bonow RO, eds. Valvular Heart Disease: A Companion to Braunwald’s Heart Disease . 4th ed. ... PA: Elsevier Saunders; 2014:chap 13. Carabello BA. Valvular heart disease. In: Goldman L, Schafer AI, eds. Goldman’s Cecil ...

  15. Aortic Valve Stenosis

    Science.gov (United States)

    ... most cases, doctors don't know why a heart valve fails to develop properly, so it isn't something you could have prevented. Calcium buildup on the valve. With age, heart valves may accumulate deposits of calcium (aortic valve ...

  16. Evaluation of the in vitro and in vivo angiogenic effects of exendin-4

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Hye-Min [Department of Anatomy and Neurobiology, Biomedical Science Institute, School of Medicine, Kyung Hee University, Seoul (Korea, Republic of); Kang, Yujung; Chun, Hyung J. [Yale Cardiovascular Research Center, Section of Cardiovascular Medicine, Department of Internal Medicine, Yale University School of Medicine, New Haven, CT (United States); Jeong, Joo-Won [Department of Anatomy and Neurobiology, Biomedical Science Institute, School of Medicine, Kyung Hee University, Seoul (Korea, Republic of); Park, Chan, E-mail: psychan@khu.ac.kr [Department of Anatomy and Neurobiology, Biomedical Science Institute, School of Medicine, Kyung Hee University, Seoul (Korea, Republic of)

    2013-04-26

    Highlights: •We investigated the effects of exendin-4 on the angiogenic process. •Exendin-4 increased migration, sprouting, and tube formation by HUVECs in in vitro. •Exendin-4 increased sprouts in aortic rings and induced new vessels in Matrigel in in vivo. •Exendin-4 may be of potential use for the treatment of vascular complications of diabetes. -- Abstract: Exendin-4, an analog of glucagon-like peptide (GLP)-1, has beneficial effects on cardiovascular disease induced by diabetes mellitus (DM). Recently, exendin-4 was reported to induce the proliferation of endothelial cells. However, its angiogenic effect on endothelial cells has not been clearly evaluated. Therefore, we investigated the effects of exendin-4 on the angiogenic process with respect to migration, sprouting, and neovascularization using in vitro and in vivo assays. Treatment with exendin-4 increased the migration of human umbilical vein endothelial cells (HUVECs) in in vitro scratch wound assays, as well as the number of lumenized vessels sprouting from HUVECs in in vitro 3D bead assays. These responses were abolished by co-treatment with exendin (9–39), a GLP-1 receptor antagonist, which suggests that exendin-4 regulates endothelial cell migration and tube formation in a GLP-1 receptor-dependent manner. In an ex vivo assay, treatment of aortic rings with exendin-4 increased the sprouting of endothelial cells. Exendin-4 also significantly increased the number of new vessels and induced blood flow in Matrigel plugs in in vivo assays. Our results provide clear evidence for the angiogenic effect of exendin-4 in in vitro and in vivo assays and provide a mechanism underlying the cardioprotective effects of exendin-4.

  17. Sex, pregnancy and aortic disease in Marfan syndrome.

    Science.gov (United States)

    Renard, Marjolijn; Muiño-Mosquera, Laura; Manalo, Elise C; Tufa, Sara; Carlson, Eric J; Keene, Douglas R; De Backer, Julie; Sakai, Lynn Y

    2017-01-01

    Sex-related differences as well as the adverse effect of pregnancy on aortic disease outcome are well-established phenomena in humans with Marfan syndrome (MFS). The underlying mechanisms of these observations are largely unknown. In an initial (pilot) step we aimed to confirm the differences between male and female MFS patients as well as between females with and without previous pregnancy. We then sought to evaluate whether these findings are recapitulated in a pre-clinical model and performed in-depth cardiovascular phenotyping of mutant male and both nulliparous and multiparous female Marfan mice. The effect of 17β-estradiol on fibrillin-1 protein synthesis was compared in vitro using human aortic smooth muscle cells and fibroblasts. Our small retrospective study of aortic dimensions in a cohort of 10 men and 20 women with MFS (10 pregnant and 10 non-pregnant) confirmed that aortic root growth was significantly increased in the pregnant group compared to the non-pregnant group (0.64mm/year vs. 0.12mm/year, p = 0.018). Male MFS patients had significantly larger aortic root diameters compared to the non-pregnant and pregnant females at baseline and follow-up (p = 0.002 and p = 0.007, respectively), but no significant increase in aortic root growth was observed compared to the females after follow-up (p = 0.559 and p = 0.352). In the GT-8/+ MFS mouse model, multiparous female Marfan mice showed increased aortic diameters when compared to nulliparous females. Aortic dilatation in multiparous females was comparable to Marfan male mice. Moreover, increased aortic diameters were associated with more severe fragmentation of the elastic lamellae. In addition, 17β-estradiol was found to promote fibrillin-1 production by human aortic smooth muscle cells. Pregnancy-related changes influence aortic disease severity in otherwise protected female MFS mice and patients. There may be a role for estrogen in the female sex protective effect.

  18. Impact of Aortic Insufficiency on Ascending Aortic Dilatation and Adverse Aortic Events After Isolated Aortic Valve Replacement in Patients With a Bicuspid Aortic Valve.

    Science.gov (United States)

    Wang, Yongshi; Wu, Boting; Li, Jun; Dong, Lili; Wang, Chunsheng; Shu, Xianhong

    2016-05-01

    Aberrant flow pattern and congenital fragility bestows bicuspid aortic valve (BAV) with a propensity toward ascending aorta dilatation, aneurysm, and dissection. Whether isolated aortic valve replacement (AVR) can prevent further dilatation in BAV ascending aorta and what indicates concurrent aortic intervention in the case of valve operation remain controversial. From June 2006 to January 2009, patients with a BAV who underwent isolated AVR were consecutively included and categorized into aortic insufficiency (BAV-AI, n = 84) and aortic stenosis (n = 112) groups, and another population of patients with a tricuspid aortic valve with aortic insufficiency (n = 149) was also recruited during the same period for comparison of annual aortic dilatation rate and adverse aortic events after isolated AVR. With a median follow-up period of 72 months (interquartile range, 66 to 78 months), ascending aorta dilatation rates were faster in the BAV-AI group than the BAV plus aortic stenosis and tricuspid aortic valve with aortic insufficiency groups (both p regression analysis identified aortic insufficiency (hazard ratio, 3.7; 95% confidence interval, 1.2 to 11.1; p = 0.019) as an independent risk factor for adverse aortic events among patients with BAV in general, whereas preoperative ascending aortic diameter larger than 45 mm (hazard ratio, 13.8; 95% confidence interval, 3.0 to 63.3; p = 0.001) served as a prognostic indicator in the BAV-AI group. An aggressive policy of preventive aortic interventions seemed appropriate in patients with BAV-AI during AVR, and BAV phenotype presenting as either insufficiency or stenosis should be taken into consideration when contemplating optimal surgical strategies for BAV aortopathy. Copyright © 2016 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

  19. Acute Aortic Arch Perforation During Transcatheter Aortic Valve Replacement in Bicuspid Aortic Stenosis and a Gothic Aortic Arch.

    Science.gov (United States)

    Millan-Iturbe, Oscar; Sawaya, Fadi J; Bieliauskas, Gintautas; Chow, Danny H F; De Backer, Ole; Søndergaard, Lars

    2017-09-01

    Transcatheter aortic valve replacement (TAVR) has evolved from a novel technology to an established therapy for high/intermediate-risk patients with severe symptomatic aortic stenosis (AS). Although TAVR is used to treat bicuspid severe AS, the large randomized trials typically excluded bicuspid AS because of its unique anatomic features. This case report describes an acute aortic perforation during delivery of a transcatheter heart valve to treat a severe bicuspid AS with a "gothic aortic arch"; more careful evaluation of the preprocedural multislice computed tomographic scan would have unveiled a sharply angulated aortic arch. This life-threatening complication was successfully treated by thoracic endovascular aortic repair. Copyright © 2017 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.

  20. A dose-effect curve of premature condensation chromosome ring in lymphocytes of human peripheral blood exposed to high dose of 60Co γ-rays in vitro

    International Nuclear Information System (INIS)

    Yao Bo; Li Yufang; Liu Guangxian; Huang Shan; Jiang Benrong; Ai Huisheng

    2009-01-01

    Objective: To establish a dose-effect curve of premature condensation chromosome ring (PCC-R) in lymphocytes of human peripheral blood after exposed to high doses of γ-rays. Methods: Peripheral blood samples was drawn from three healthy individuals, and exposed to 60 Co γ-rays with doses between 0 and 30 Gy. The frequencies of PCC-R in premature condensation chromosome (PCC) cells obtained by Okadaic acid (OA) induction were calculated, and a dose-effect curve was fitted. Results: PCC index tapered with dose. Frequencies of PCC-R per cell increased until 20 Gy, and then saturation was observed. The results were fitted to a lineal model up to 20 Gy: y=-0.020 + 0.052D, where y was the frequencies of PCC-R per cell, D was the radiation dose(Gy). Conclusions: The highest dose could be estimated is 20 Gy by the dose-effect curve established with PCC-R method. Its utility and validity will be verified in the future application of radiation accident. (authors)

  1. Neonatal aortic stenosis.

    Science.gov (United States)

    Drury, Nigel E; Veldtman, Gruschen R; Benson, Lee N

    2005-09-01

    Neonatal aortic stenosis is a complex and heterogeneous condition, defined as left ventricular outflow tract obstruction at valvular level, presenting and often requiring treatment in the first month of life. Initial presentation may be catastrophic, necessitating hemodynamic, respiratory and metabolic resuscitation. Subsequent management is focused on maintaining systemic blood flow, either via a univentricular Norwood palliation or a biventricular route, in which the effective aortic valve area is increased by balloon dilation or surgical valvotomy. In infants with aortic annular hypoplasia but adequately sized left ventricle, the Ross-Konno procedure is also an attractive option. Outcomes after biventricular management have improved in recent years as a consequence of better patient selection, perioperative management and advances in catheter technology. Exciting new developments are likely to significantly modify the natural history of this disorder, including fetal intervention for the salvage of the hypoplastic left ventricle; 3D echocardiography providing better definition of valve morphology and aiding patient selection for a surgical or catheter-based intervention; and new transcutaneous approaches, such as duel beam echo, to perforate the valve.

  2. Transesophageal echocardiographic strain imaging predicts aortic biomechanics: Beyond diameter.

    Science.gov (United States)

    Emmott, Alexander; Alzahrani, Haitham; Alreishidan, Mohammed; Therrien, Judith; Leask, Richard L; Lachapelle, Kevin

    2018-03-11

    Clinical guidelines recommend resection of ascending aortic aneurysms at diameters 5.5 cm or greater to prevent rupture or dissection. However, approximately 40% of all ascending aortic dissections occur below this threshold. We propose new transesophageal echocardiography strain-imaging moduli coupled with blood pressure measurements to predict aortic dysfunction below the surgical threshold. A total of 21 patients undergoing aortic resection were recruited to participate in this study. Transesophageal echocardiography imaging of the aortic short-axis and invasive radial blood pressure traces were taken for 3 cardiac cycles. By using EchoPAC (GE Healthcare, Madison, Wis) and postprocessing in MATLAB (MathWorks, Natick, Mass), circumferential stretch profiles were generated and combined with the blood pressure traces. From these data, 2 in vivo stiffness moduli were calculated: the Cardiac Cycle Pressure Modulus and Cardiac Cycle Stress Modulus. From the resected aortic ring, testing squares were isolated for ex vivo mechanical analysis and histopathology. Each square underwent equibiaxial tensile testing to generate stress-stretch profiles for each patient. Two ex vivo indices were calculated from these profiles (energy loss and incremental stiffness) for comparison with the Cardiac Cycle Pressure Modulus and Cardiac Cycle Stress Modulus. The echo-derived stiffness moduli demonstrate positive significant covariance with ex vivo tensile biomechanical indices: energy loss (vs Cardiac Cycle Pressure Modulus: R 2  = 0.5873, P biomechanics and histopathology, which demonstrates the added benefit of using simple echocardiography-derived biomechanics to stratify patient populations. Copyright © 2018. Published by Elsevier Inc.

  3. In vitro study on the effects of some selected agonists and antagonists of alpha(1)-adrenergic receptors on the contractility of the aneurysmally-changed aortic smooth muscle in humans.

    Science.gov (United States)

    Gnus, J; Czerski, A; Ferenc, S; Zawadzki, W; Witkiewicz, W; Hauzer, W; Rusiecka, A; Bujok, J

    2012-02-01

    The study included 18 sections of the aneurysmally-changed abdominal aortas, obtained from patients of the Provincial Specialist Hospital in Wroclaw and 18 sections of normal abdominal aortas obtained from swine. The collected samples were placed horizontally in the incubation chamber. Changes in their transverse section area were registered. They were stretched to a tension of 5 mN. Krebs-Henseleit buffer was used as the incubatory environment. Incubation of the sections was performed at a temperature of 37°C, in the gaseous mixture of oxygen and carbon dioxide used in the following proportion: 95% of O(2) and 5% of CO(2). Contractions of the aorta were registered with isotonic transducers (Letica Scientific Instruments). In the studies, we examined the influence of α(1)-adrenergic receptors (and their subtypes α(1A), α(1B), α(1D)) on the contractility of the aortic muscle in humans and swine by their stimulation or inhibition with some selected agonists or antagonists. This time, it was shown that the stimulation of α(1)-adrenergic receptors leads to contractions of the human and swine aortic muscle; the observed increase in the muscle tone may follow from the stimulation of all subtypes of alpha-1 receptor (α(1A), α(1B), α(1D)). All three subtypes of 1-adrenergic receptor are engaged in vasoconstriction, especially of α(1A) and α(1D) subtypes; the α(1B) subtype is less significant for aortic contractility. The contractile response of the aneurysmally-changed abdominal aorta in humans to agonists of α-adrenergic receptors was significantly less intense than that of the normal porcine aorta. It can be concluded that aneurysms influence the contractile response of the aorta.

  4. MRI-based multiscale models for the hemodynamic and structural evaluation of surgically reconstructed aortic arches

    DEFF Research Database (Denmark)

    Pittaccio, S; Migliavacca, F; Balossino, R

    2007-01-01

    ) geometries of a porcine aortic arch were derived from magnetic resonance imaging (MRI) images. Inlet conditions were derived from MRI velocimetry. A multiscale approach was used for the imposition of outlet conditions, wherein a lumped parameter net provided an active afterload. Evidence was found that ring...

  5. Aortic obstruction: anatomy and echocardiography

    Directory of Open Access Journals (Sweden)

    Keirns Candace

    2006-09-01

    Full Text Available Abstract Echocardiography is a valuable non-invasive technique for identifying the site and type of aortic obstruction. Knowledge of the morphological details of each type of obstruction is the basis for correct interpretation of the diagnostic images and clinical decisions. This study was undertaken to correlate the echocardiographic images with anatomic specimens of equivalent valvular and supravalvular aortic obstruction. Specimens were part of the collection of the Department of Embryology. Fifty six patients were studied, and forty specimens with aortic obstruction were analyzed. Echocardiographic characteristics: Thirty one (55.3% patients were women and twenty five (44.7% men. Valvular aortic obstruction was found in Thirty six patients (64.3 % and supravalvular aortic obstruction in twenty (35.7%. Anatomic characteristics: Of the forty specimens examined, twenty one (52.5% had valvular aortic obstruction and nineteen (47.5% supravalvular aortic obstruction. The anatomoechocardiographic correlation clearly showed that the anatomic findings of the specimen hearts and aortas corresponded to echocardiographic images of valvular and supravalvular aortic obstruction and provided solid corroboration of echocardiographic diagnoses.

  6. Acute Aortic Arch Perforation During Transcatheter Aortic Valve Replacement in Bicuspid Aortic Stenosis and a Gothic Aortic Arch

    DEFF Research Database (Denmark)

    Millan-Iturbe, Oscar; Sawaya, Fadi J.; Bieliauskas, Gintautas

    2017-01-01

    AS because of its unique anatomic features. This case report describes an acute aortic perforation during delivery of a transcatheter heart valve to treat a severe bicuspid AS with a “gothic aortic arch”; more careful evaluation of the preprocedural multislice computed tomographic scan would have unveiled...

  7. Minimally invasive aortic valve replacement

    DEFF Research Database (Denmark)

    Foghsgaard, Signe; Schmidt, Thomas Andersen; Kjaergard, Henrik K

    2009-01-01

    In this descriptive prospective study, we evaluate the outcomes of surgery in 98 patients who were scheduled to undergo minimally invasive aortic valve replacement. These patients were compared with a group of 50 patients who underwent scheduled aortic valve replacement through a full sternotomy...... operations were completed as mini-sternotomies, 4 died later of noncardiac causes. The aortic cross-clamp and perfusion times were significantly different across all groups (P replacement...... is an excellent operation in selected patients, but its true advantages over conventional aortic valve replacement (other than a smaller scar) await evaluation by means of randomized clinical trial. The "extended mini-aortic valve replacement" operation, on the other hand, is a risky procedure that should...

  8. Acute Type II Aortic Dissection with Severe Aortic Regurgitation and Chronic Descending Aortic Dissection in Pregnant Patient with Marfan Syndrome.

    Science.gov (United States)

    Lee, Seok-Soo; Jung, Tae-Eun; Lee, Dong Hyup

    2012-12-01

    Aortic dilatation and dissection are severe complications during pregnancy that can be fatal to both the mother and the fetus. The risks of these complications are especially high in pregnant patients with Marfan syndrome; however, incidents of descending aortic dissection are very rare. This case report involves a successful Bentall procedure for and recovery from a rare aortic dissection in a pregnant Marfan patient who developed acute type II aortic dissection with severe aortic regurgitation and chronic descending aortic dissection immediately after Cesarean section. Regular follow-up will be needed to monitor the descending aortic dissection.

  9. Abdominal Aortic Emergencies.

    Science.gov (United States)

    Lech, Christie; Swaminathan, Anand

    2017-11-01

    This article discusses abdominal aortic emergencies. There is a common thread of risk factors and causes of these diseases, including age, male gender, hypertension, dyslipidemia, and connective tissue disorders. The most common presenting symptom of these disorders is pain, usually in the chest, flank, abdomen, or back. Computed tomography scan is the gold standard for diagnosis of pathologic conditions of the aorta in the hemodynamically stable patient. Treatment consists of a combination of blood pressure and heart rate control and, in many cases, emergent surgical intervention. Copyright © 2017 Elsevier Inc. All rights reserved.

  10. Acute Type II Aortic Dissection with Severe Aortic Regurgitation and Chronic Descending Aortic Dissection in Pregnant Patient with Marfan Syndrome

    OpenAIRE

    Lee, Seok-Soo; Jung, Tae-Eun; Lee, Dong Hyup

    2012-01-01

    Aortic dilatation and dissection are severe complications during pregnancy that can be fatal to both the mother and the fetus. The risks of these complications are especially high in pregnant patients with Marfan syndrome; however, incidents of descending aortic dissection are very rare. This case report involves a successful Bentall procedure for and recovery from a rare aortic dissection in a pregnant Marfan patient who developed acute type II aortic dissection with severe aortic regurgitat...

  11. Valve-sparing aortic root replacement and aortic valve repair in a patient with acromegaly and aortic root dilatation

    Directory of Open Access Journals (Sweden)

    Karel Van Praet

    2015-07-01

    Full Text Available Aortic regurgitation and dilatation of the aortic root and ascending aorta are severe complications of acromegaly. The current trend for management of an aortic root aneurysm is valve-sparing root replacement as well as restoring the diameter of the aortic sinotubular junction (STJ and annulus. Our case report supports the recommendation that in patients with acromegaly, severe aortic root involvement may indicate the need for surgery.

  12. Kayser-Fleischer Rings

    Science.gov (United States)

    ... Support Contacts Lab Tracker/Copper Calculator Stories Programs & Research ... About Everything you need to know about Wilson Disease Kayser-Fleischer Rings Definition Kayser-Fleischer Ring: Clinical sign. Brownish-yellow ring visible around the corneo- ...

  13. ASSOCIATIVE RINGS SOLVED AS LIE RINGS

    Directory of Open Access Journals (Sweden)

    M. B. Smirnov

    2011-01-01

    Full Text Available The paper has proved that an associative ring which is solvable of a n- class as a Lie ring has a nilpotent ideal of the nilpotent class not more than 3×10n–2  and a corresponding quotient ring satisfies an identity [[x1, x2, [x3, x4

  14. Unusual Case of Overt Aortic Dissection Mimicking Aortic Intramural Hematoma

    Directory of Open Access Journals (Sweden)

    Kushtrim Disha

    2016-04-01

    Full Text Available We report an interesting case in which overt aortic dissection mimicked two episodes of aortic intramural hematoma (IMH (Stanford A, DeBakey I. This took place over the course of four days and had a major influence on the surgical treatment strategy. The first episode of IMH regressed completely within 15 hours after it was clinically diagnosed and verified using imaging techniques. The recurrence of IMH was detected three days thereafter, resulting in an urgent surgical intervention. Overt aortic dissection with evidence of an intimal tear was diagnosed intraoperatively.

  15. Aortic root replacement after previous surgical intervention on the aortic valve, aortic root, or ascending aorta.

    Science.gov (United States)

    Kirsch, E W Matthias; Radu, N Costin; Mekontso-Dessap, Armand; Hillion, Marie-Line; Loisance, Daniel

    2006-03-01

    Aortic root replacement after a previous operation on the aortic valve, aortic root, or ascending aorta remains a major challenge. Records of 56 consecutive patients (44 men; mean age, 56.4 +/- 13.6 years) undergoing reoperative aortic root replacement between June 1994 and June 2005 were reviewed retrospectively. Reoperation was performed 9.4 +/- 6.7 years after the last cardiac operation. Indications for reoperation were true aneurysm (n = 14 [25%]), false aneurysm (n = 10 [18%]), dissection or redissection (n = 9 [16%]), structural or nonstructural valve dysfunction (n = 10 [18%]), prosthetic valve-graft infection (n = 12 [21%]), and miscellaneous (n = 1 [2%]). Procedures performed were aortic root replacement (n = 47 [84%]), aortic root replacement plus mitral valve procedure (n = 5 [9%]), and aortic root replacement plus arch replacement (n = 4 [7%]). In 14 (25%) patients coronary artery bypass grafting had to be performed unexpectedly during the same procedure or immediately after the procedure to re-establish coronary perfusion. Hospital mortality reached 17.9% (n = 10). Multivariate logistic regression analysis revealed the need for unplanned perioperative coronary artery bypass grafting as the sole independent risk factor for hospital death (P = .005). Actuarial survival was 83.8% +/- 4.9% at 1 month, 73.0% +/- 6.3% at 1 year, and 65.7% +/- 9.0% at 5 years after the operation. One patient had recurrence of endocarditis 6.7 months after the operation and required repeated homograft aortic root replacement. Reoperative aortic root replacement remains associated with a high postoperative mortality. The need to perform unplanned coronary artery bypass grafting during reoperative aortic root replacement is a major risk factor for hospital death. The optimal technique for coronary reconstruction in this setting remains to be debated.

  16. Current indications for stentless aortic bioprostheses.

    Science.gov (United States)

    Hegazy, Yasser Y; Rayan, Amr; Bauer, Stefan; Keshk, Noha; Bauer, Kerstin; Ennker, Ina; Ennker, Jürgen

    2018-01-01

    The best aortic prostheses have been debated for decades. The introduction of stentless aortic bioprostheses was aimed at improving hemodynamics and potentially the durability of aortic bioprostheses. Despite the good short- and long-term outcomes after implantation of stentless aortic bioprostheses, their use remains limited owing to the technically demanding implantation techniques. Nevertheless, stentless aortic bioprostheses might be of special benefit in certain indications, where they could be a valuable addition to the surgical armamentarium.

  17. Tobacco smoking and aortic aneurysm

    DEFF Research Database (Denmark)

    Sode, Birgitte F; Nordestgaard, Børge; Grønbæk, Morten

    2013-01-01

    BACKGROUND: We determined the predictive power of tobacco smoking on aortic aneurysm as opposed to other risk factors in the general population. METHODS: We recorded tobacco smoking and other risk factors at baseline, and assessed hospitalization and death from aortic aneurysm in 15,072 individuals...... aneurysm in males and females consuming above 20g tobacco daily was 3.5% and 1.3%, among those >60years with plasma cholesterol >5mmol/L and a systolic blood pressure >140mmHg. CONCLUSIONS: Tobacco smoking is the most important predictor of future aortic aneurysm outcomes in the general population...

  18. Reoperative Aortic Root Replacement in Patients with Previous Aortic Root or Aortic Valve Procedures

    Directory of Open Access Journals (Sweden)

    Byung Kwon Chong

    2016-08-01

    Full Text Available Background: Generalization of standardized surgical techniques to treat aortic valve (AV and aortic root diseases has benefited large numbers of patients. As a consequence of the proliferation of patients receiving aortic root surgeries, surgeons are more frequently challenged by reoperative aortic root procedures. The aim of this study was to evaluate the outcomes of redo-aortic root replacement (ARR. Methods: We retrospectively reviewed 66 patients (36 male; mean age, 44.5±9.5 years who underwent redo-ARR following AV or aortic root procedures between April 1995 and June 2015. Results: Emergency surgeries comprised 43.9% (n=29. Indications for the redo-ARR were aneurysm (n=12, pseudoaneurysm (n=1, or dissection (n=6 of the residual native aortic sinus in 19 patients (28.8%, native AV dysfunction in 8 patients (12.1%, structural dysfunction of an implanted bioprosthetic AV in 19 patients (28.8%, and infection of previously replaced AV or proximal aortic grafts in 30 patients (45.5%. There were 3 early deaths (4.5%. During follow- up (median, 54.65 months; quartile 1–3, 17.93 to 95.71 months, there were 14 late deaths (21.2%, and 9 valve-related complications including reoperation of the aortic root in 1 patient, infective endocarditis in 3 patients, and hemorrhagic events in 5 patients. Overall survival and event-free survival rates at 5 years were 81.5%±5.1% and 76.4%±5.4%, respectively. Conclusion: Despite technical challenges and a high rate of emergency conditions in patients requiring redo-ARR, early and late outcomes were acceptable in these patients.

  19. Stirling engine piston ring

    Science.gov (United States)

    Howarth, Roy B.

    1983-01-01

    A piston ring design for a Stirling engine wherein the contact pressure between the piston and the cylinder is maintained at a uniform level, independent of engine conditions through a balancing of the pressure exerted upon the ring's surface and thereby allowing the contact pressure on the ring to be predetermined through the use of a preloaded expander ring.

  20. The bicuspid aortic valve and its relation to aortic dilation

    Directory of Open Access Journals (Sweden)

    Shi-Min Yuan

    2010-01-01

    Full Text Available BACKGROUND: A bicuspid aortic valve (BAV is a common congenital heart disease, which affects 1-2% of the population. However, the relationship between BAVs and aortic dilation has not been sufficiently elucidated. METHODS: A total of 241 BAV patients who were referred to this hospital for cardiac surgey over a 4.75-year period were included in this study. In addition to the clinical characteristics of the included patients, the morphological features of the aortic valve and aorta, the length of the left main coronary artery, and the laboratory findings (the coagulation and hematological parameters as well as the total cholesterol concentration were determined and compared with those of the tricuspid aortic valve (TAV patients. RESULTS: The BAV patients were younger than the TAV patients for a valve surgery in the last 3 months of the study period. The BAV patients were predominantly male. Most of the BAVs that were surgically treated were stenotic, regurgitant, or combined, and only 19 (7.88% were normally functioning valves. According to echocardiography or operative records, 148 (78.31% were type A, 31 (16.40% were type B, and 10 (5.29% were type C. The left main coronary artery was much shorter in the BAV patients than it was in the TAV patients. There was no significant difference between BAV and TAV patients in the total cholesterol concentrations; whereas differences were noted between patients receiving lipid-lowering therapy and those not receiving lipid-lowering therapy. The dimensions of the aortic root, sinotubular junction, and ascending aorta were beyond normal limits, while they were significantly smaller in the BAV patients than in the TAV patients. They were also much smaller in patients receiving statin therapy than those not receiving statin therapy in both groups. Moreover, the aortic dilation in the BAV group was found to be significantly associated with patient age. CONCLUSIONS: The BAV patients developed aortic wall and

  1. Abdominal aortic aneurysms

    DEFF Research Database (Denmark)

    Lindholt, Jes S.

    2010-01-01

    Although the number of elective operations for abdominal aortic aneurysms (AAA) is increasing, the sex- and age-standardised mortality rate of AAAs continues to rise, especially among men aged 65 years or more. The lethality of ruptured AAA continues to be 80-95%, compared with 5-7% by elective...... surgery of symptomfree AAA. In order to fulfil all WHO, European, and Danish criteria for screening, a randomised hospitalbased screening trial of 12,639 65-73 year old men in Viborg County (Denmark) was initiated in 1994. It seemed that US screening is a valid, suitable and acceptable method of screening...... patients without previous hospital discharge diagnoses due to cardiovascular disease than among similar men without AAA. The absolute risk difference after 5 years was 16%. So, they will benefit from general cardiovascular preventive action as smoking cessation, statins and low-dose aspirin, which could...

  2. Abdominal aortic aneurysm surgery

    DEFF Research Database (Denmark)

    Gefke, K; Schroeder, T V; Thisted, B

    1994-01-01

    The goal of this study was to identify patients who need longer care in the ICU (more than 48 hours) following abdominal aortic aneurysm (AAA) surgery and to evaluate the influence of perioperative complications on short- and long-term survival and quality of life. AAA surgery was performed in 553...... patients, 51 (9%) of whom died within the first 48 hours. Of the 502 patients who survived for more than 48 hours, 109 required ICU therapy for more than 48 hours, whereas 393 patients were in the ICU for less than 48 hours. The incidence of preoperative risk factors was similar for the two groups...... combined failed to permit identification of patients in whom the perioperative survival rate was 0%. Even 20% of patients with multiorgan failure survived for 6 months. Of those patients who needed ICU therapy for more than 48 hours, 41 (38%) were alive at the end of 1988. In response to a questionnaire...

  3. Evaluation of the aortic anulus

    International Nuclear Information System (INIS)

    Link, K.M.; Margosian, P.

    1991-01-01

    This paper evaluates the efficacy of echocardiography and MR imaging for measuring the aortic anulus in patients who are candidates for aortic valve replacement. The MR imaging study was performed on a 1.5-T system, and the results were compared with echocardiography results obtained with use of a Toshiba system with a 2.5-mHz transducer. The aortic valve anulus was evaluated in the coronal, long-axis, and short-axis views with the MR imaging technique and in the right parasternal suprasternal, and apical projections with the echocardiographic technique. Twenty-four patients studied with MR imaging and echocardiography went on to have aortic valve replacement. When compared with surgical results, MR imaging had an r value of .95 while echocardiography had an r value of .70

  4. Alternative loop rings

    CERN Document Server

    Goodaire, EG; Polcino Milies, C

    1996-01-01

    For the past ten years, alternative loop rings have intrigued mathematicians from a wide cross-section of modern algebra. As a consequence, the theory of alternative loop rings has grown tremendously. One of the main developments is the complete characterization of loops which have an alternative but not associative, loop ring. Furthermore, there is a very close relationship between the algebraic structures of loop rings and of group rings over 2-groups. Another major topic of research is the study of the unit loop of the integral loop ring. Here the interaction between loop rings and group ri

  5. Imaging techniques in transcatheter aortic valve replacement

    Directory of Open Access Journals (Sweden)

    Quaife RA

    2013-11-01

    Full Text Available Robert A Quaife, Jennifer Dorosz, John C Messenger, Ernesto E Salcedo Division of Cardiology, University of Colorado, Aurora, CO, USA Abstract: Calcific aortic stenosis is now understood as a complex valvular degenerative process sharing many risk factors with atherosclerosis. Once patients develop symptomatic calcific aortic stenosis, the only effective treatment is aortic valve replacement. In the past decade, transcatheter aortic valve replacement (TAVR has been developed as an alternative to surgery to treat severe calcific aortic stenosis. Cardiac imaging plays a pivotal role in the contemporary management of patients with calcific aortic stenosis, and particularly in patients being considered for TAVR, who demand detailed imaging of the aortic valve apparatus. In this review, we highlight the role of cardiac imaging for patient selection, procedural guidance, and evaluation of results of TAVR. Keywords: aortic stenosis, cardiovascular imaging, transcutaneous aortic valve replacement

  6. Transcatheter aortic valve implantation of the direct flow medical aortic valve with minimal or no contrast

    Energy Technology Data Exchange (ETDEWEB)

    Latib, Azeem, E-mail: alatib@gmail.com [Interventional Cardiology Unit, San Raffaele Scientific Institute and EMO-GVM Centro Cuore Columbus, Milan (Italy); Maisano, Francesco; Colombo, Antonio [Interventional Cardiology Unit, San Raffaele Scientific Institute and EMO-GVM Centro Cuore Columbus, Milan (Italy); Klugmann, Silvio [Azienda Ospedaliera Niguarda Ca Granda, Piazza Ospedale Maggiore 3, Milan (Italy); Low, Reginald; Smith, Thomas [University of California Davis, Davis, CA 95616 (United States); Davidson, Charles [Northwestern Memorial Hospital, Chicago, IL 60611 (United States); Harreld, John H. [Clinical Imaging Analytics, Guerneville, CA (United States); Bruschi, Giuseppe; DeMarco, Federico [Azienda Ospedaliera Niguarda Ca Granda, Piazza Ospedale Maggiore 3, Milan (Italy)

    2014-06-15

    The 18F Direct Flow Medical (DFM) THV has conformable sealing rings, which minimizes aortic regurgitation and permits full hemodynamic assessment of valve performance prior to permanent implantation. During the DISCOVER trial, three patients who were at risk for receiving contrast media, two due to severe CKD and one due to a recent hyperthyroid reaction to contrast, underwent DFM implantation under fluoroscopic and transesophageal guidance without aortography during either positioning or to confirm the final position. Valve positioning was based on the optimal angiographic projection as calculated by the pre-procedural multislice CT scan. Precise optimization of valve position was performed to minimize transvalve gradient and aortic regurgitation. Prior to final implantation, transvalve hemodynamics were assessed invasively and by TEE. The post-procedure mean gradients were 7, 10, 11 mm Hg. The final AVA by echo was 1.70, 1.40 and 1.68 cm{sup 2}. Total aortic regurgitation post-procedure was none or trace in all three patients. Total positioning and assessment of valve performance time was 4, 6, and 12 minutes. Contrast was only used to confirm successful percutaneous closure of the femoral access site. The total contrast dose was 5, 8, 12 cc. Baseline eGFR and creatinine was 28, 22, 74 mL/min/1.73 m{sup 2} and 2.35, 2.98, and 1.03 mg/dL, respectively. Renal function was unchanged post-procedure: eGFR = 25, 35, and 96 mL/min/1.73 m{sup 2} and creatinine = 2.58, 1.99, and 1.03 mg/dL, respectively. In conclusion, the DFM THV provides the ability to perform TAVI with minimal or no contrast. The precise and predictable implantation technique can be performed with fluoro and echo guidance.

  7. Alkaptonuria-associated aortic stenosis.

    Science.gov (United States)

    Lok, Zoe S Y; Goldstein, Jacob; Smith, Julian A

    2013-07-01

    Alkaptonuria is an autosomal recessive disorder of tyrosine metabolism, which results in accumulation of unmetabolized homogentisic acid and its oxidized product in various tissues, including the heart. Cardiovascular involvement is a rare but serious complication of the disease. We present two patients who have undergone successful aortic valve replacement for alkaptonuria-associated aortic stenosis along with a review of the literature. © 2013 Wiley Periodicals, Inc.

  8. Relation of murine thoracic aortic structural and cellular changes with aging to passive and active mechanical properties.

    Science.gov (United States)

    Wheeler, Jason B; Mukherjee, Rupak; Stroud, Robert E; Jones, Jeffrey A; Ikonomidis, John S

    2015-02-25

    Maintenance of the structure and mechanical properties of the thoracic aorta contributes to aortic function and is dependent on the composition of the extracellular matrix and the cellular content within the aortic wall. Age-related alterations in the aorta include changes in cellular content and composition of the extracellular matrix; however, the precise roles of these age-related changes in altering aortic mechanical function are not well understood. Thoracic aortic rings from the descending segment were harvested from C57BL/6 mice aged 6 and 21 months. Thoracic aortic diameter and wall thickness were higher in the old mice. Cellular density was reduced in the medial layer of aortas from the old mice; concomitantly, collagen content was higher in old mice, but elastin content was similar between young and old mice. Stress relaxation, an index of compliance, was reduced in aortas from old mice and correlated with collagen fraction. Contractility of the aortic rings following potassium stimulation was reduced in old versus young mice. Furthermore, collagen gel contraction by aortic smooth muscle cells was reduced with age. These results demonstrate that numerous age-related structural changes occurred in the thoracic aorta and were related to alterations in mechanical properties. Aortic contractility decreased with age, likely because of a reduction in medial cell number in addition to a smooth muscle contractile deficit. Together, these unique findings provide evidence that the age-related changes in structure and mechanical function coalesce to provide an aortic substrate that may be predisposed to aortopathies. © 2015 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.

  9. Results of aortic root reimplantation in patients with ascending aortic aneurysm and concomitant aortic insufficiency

    Directory of Open Access Journals (Sweden)

    А. М. Чернявский

    2016-01-01

    Full Text Available Objective. The research was designed to evaluate the results of valve-sparing operations: aortic root reimplantation versus aortic valve reimplantation when repairing an ascending aortic aneurysm with concomitant aortic insufficiency.Methods. Within a blind prospective randomized study conducted over a period from 2011 to 2015, 64 patients underwent aortic valve-sparing surgery. The inclusion criteria were the presence of an aortic aneurysm of the ascending aorta exceeding 4.5 cm and concomitant aortic insufficiency. All patients were divided into two groups: FS-group, aortic root reimplantation (modified Florida Sleeve technique (n = 32 and D-group, aortic valve reimplantation (David procedure (n = 32. The average age of patients was 57±13 (23–73 years in the FS-group and 55±11 (15–72 years in the D-group (p = 0.54. Both groups had 78% of males (p>0.99. A Marfan syndrome was identified in 6% and 9% in the FS-group and D-group respectively (p>0.99. Mean diameter of the sinuses of Valsalva was 51±7 mm and 56±10 mm (p = 0.09, aortic insufficiency 2.6±0.7 and 2.8±0.8 (p = 0.15 in the FS-group and D-group respectively. In the FS-group and D-group LVEDD amounted to 5.5±0.7 mm and 5.9±1.0 mm (p = 0.09 respectively. All patients took echocardiography in the preoperative, postoperative and follow-up periods.Results. In the long-term period, the degree of aortic regurgitation was 1.2±0.1 in the FS-group and 1.3±0.6 in the D-group (p = 0.72. LVEDD was 123±23 mm in the FS-group and 139.6±80 mm in the D-group at follow-up (p = 0.77. There were no statistically significant differences in the analysis of complications. Overall 30-day in-hospital mortality was 7.8%. There were 2 (6.3% deaths in the FS-group and 3 (9.4% in the D-group (p = 0.5.Late mortality was 6.3% in the FS-group and 3.1% in the D-group (p>0.99. Cumulative survival at 4 years was 84.3% and 84.8% in the FS-group and the D-group respectively (p = 0.94. Cumulative freedom from

  10. Prenatal Diagnosis of a Fetus with Congenital Heart Defect and Ring Chromosome 14

    Directory of Open Access Journals (Sweden)

    Javier Sánchez

    2012-01-01

    Full Text Available Monosomy of chromosome 14 has been reported in only a few prenatal cases. Generally, this monosomy is associated with a mosaicism of ring chromosome 14. Ring chromosome 14 is a rare cytogenetic entity with clinical characteristics that include growth retardation, facial dysmorphia, hypotonia, seizures, and retinitis pigmentosa. Given that the majority of symptoms appear postnatally, few cases have been reported of prenatal diagnosis of mosaicism monosomy/ring chromosome 14. We describe the prenatal diagnosis of a case of chromosomal mosaicism, a cell line with ring chromosome 14, r(14, and a second cell line with monosomy 14, in a fetus with aortic coarctation and chamber asymmetry. This is the first case of a prenatal diagnosis associating mosaicism with ring chromosome 14, monosomy 14, and fetal cardiopathy. We identified the exact breakpoint in ring chromosome 14 in IGH locus, which may provide further insight into the mode of ring formation as well as prenatal findings.

  11. Wall stress on ascending thoracic aortic aneurysms with bicuspid compared with tricuspid aortic valve.

    Science.gov (United States)

    Xuan, Yue; Wang, Zhongjie; Liu, Raymond; Haraldsson, Henrik; Hope, Michael D; Saloner, David A; Guccione, Julius M; Ge, Liang; Tseng, Elaine

    2018-03-08

    Guidelines for repair of bicuspid aortic valve-associated ascending thoracic aortic aneurysms have been changing, most recently to the same criteria as tricuspid aortic valve-ascending thoracic aortic aneurysms. Rupture/dissection occurs when wall stress exceeds wall strength. Recent studies suggest similar strength of bicuspid aortic valve versus tricuspid aortic valve-ascending thoracic aortic aneurysms; thus, comparative wall stress may better predict dissection in bicuspid aortic valve versus tricuspid aortic valve-ascending thoracic aortic aneurysms. Our aim was to determine whether bicuspid aortic valve-ascending thoracic aortic aneurysms had higher wall stresses than their tricuspid aortic valve counterparts. Patients with bicuspid aortic valve- and tricuspid aortic valve-ascending thoracic aortic aneurysms (bicuspid aortic valve = 17, tricuspid aortic valve = 19) greater than 4.5 cm underwent electrocardiogram-gated computed tomography angiography. Patient-specific 3-dimensional geometry was reconstructed and loaded to systemic pressure after accounting for prestress geometry. Finite element analyses were performed using the LS-DYNA solver (LSTC Inc, Livermore, Calif) with user-defined fiber-embedded material model to determine ascending thoracic aortic aneurysm wall stress. Bicuspid aortic valve-ascending thoracic aortic aneurysms 99th-percentile longitudinal stresses were 280 kPa versus 242 kPa (P = .028) for tricuspid aortic valve-ascending thoracic aortic aneurysms in systole. These stresses did not correlate to diameter for bicuspid aortic valve-ascending thoracic aortic aneurysms (r = -0.004) but had better correlation to tricuspid aortic valve-ascending thoracic aortic aneurysms diameter (r = 0.677). Longitudinal stresses on sinotubular junction were significantly higher in bicuspid aortic valve-ascending thoracic aortic aneurysms than in tricuspid aortic valve-ascending thoracic aortic aneurysms (405 vs 329 kPa, P = .023). Bicuspid

  12. Bovine aortic arch: A novel association with thoracic aortic dilation

    International Nuclear Information System (INIS)

    Malone, C.D.; Urbania, T.H.; Crook, S.E.S.; Hope, M.D.

    2012-01-01

    Aim: To investigate whether there is a link between bovine arch and thoracic aortic aneurysm. Materials and methods: Computed tomography (CT) and magnetic resonance imaging (MRI) images of the thorax of 191 patients with dilated thoracic aortas and 391 consecutive, unselected patients as controls were retrospectively reviewed. Bovine arch was considered present if either a shared origin of the left common carotid and innominate arteries or an origin of the left common carotid from the innominate artery was identified. A chi-square test was used to evaluate the significance of differences between subgroups. Results: A trend towards increased prevalence of bovine arch was seen in patients with dilated aortas (26.2%) compared to controls (20.5%, p = 0.12). The association was statistically significant in patients over 70 years old (31.9%, p = 0.019) and when dilation involved the aortic arch (47.6%, p = 0.003). Conclusions: An association between bovine arch and aortic dilation is seen in older patients, and when dilation involves the aortic arch. Bovine arch should be considered a potential risk factor for thoracic aortic aneurysm.

  13. Endoluminal treatment of aortic dissection

    Energy Technology Data Exchange (ETDEWEB)

    Chavan, Ajay; Lotz, Joachim; Galanski, Michael [Department of Diagnostic Radiology, Hannover Medical School, Carl Neuberg Strasse 1, 30625, Hannover (Germany); Oelert, Frank; Haverich, Axel; Karck, Matthias [Department of Thoracic and Cardiovascular Surgery, Hannover Medical School, Carl Neuberg Strasse 1, 30625, Hannover (Germany)

    2003-11-01

    Aortic dissection is most often a catastrophic medical emergency which, if untreated, can be potentially fatal. The intention of therapy in patients with aortic dissection is to prevent aortic rupture or aneurysm formation as well as to relieve branch vessel ischaemia. Patients with aortic dissection are often poor candidates for anaesthesia and surgery and the surgical procedure itself is challenging requiring thoracotomy, aortic cross clamping, blood transfusion as well as prolonged hospital stay in some cases. Operative mortality is especially high in patients with critical mesenteric or renal ischaemia. The past decade has experienced the emergence of a number of interventional radiological or minimally invasive techniques which have significantly improved the management of patients with aortic dissection. These include stent grafting for entry site closure to prevent aneurysmatic widening of the false lumen as well as percutaneous techniques such as balloon fenestration of the intimal flap and aortic true lumen stenting to alleviate branch vessel ischaemia. False lumen thrombosis following entry closure with stent grafts has been observed in 86-100% of patients, whereas percutaneous interventions are able to effectively relieve organ ischaemia in approximately 90% of the cases. In the years to come, it is to be expected that these endoluminal techniques will become the method of choice for treating most type-B dissections and will assist in significantly reducing the number of open surgical procedures required for type-A dissections. The intention of this article is to provide an overview of the current status of these endoluminal techniques based on our own experience as well as on a review of the relevant literature. (orig.)

  14. Endoluminal treatment of aortic dissection

    International Nuclear Information System (INIS)

    Chavan, Ajay; Lotz, Joachim; Galanski, Michael; Oelert, Frank; Haverich, Axel; Karck, Matthias

    2003-01-01

    Aortic dissection is most often a catastrophic medical emergency which, if untreated, can be potentially fatal. The intention of therapy in patients with aortic dissection is to prevent aortic rupture or aneurysm formation as well as to relieve branch vessel ischaemia. Patients with aortic dissection are often poor candidates for anaesthesia and surgery and the surgical procedure itself is challenging requiring thoracotomy, aortic cross clamping, blood transfusion as well as prolonged hospital stay in some cases. Operative mortality is especially high in patients with critical mesenteric or renal ischaemia. The past decade has experienced the emergence of a number of interventional radiological or minimally invasive techniques which have significantly improved the management of patients with aortic dissection. These include stent grafting for entry site closure to prevent aneurysmatic widening of the false lumen as well as percutaneous techniques such as balloon fenestration of the intimal flap and aortic true lumen stenting to alleviate branch vessel ischaemia. False lumen thrombosis following entry closure with stent grafts has been observed in 86-100% of patients, whereas percutaneous interventions are able to effectively relieve organ ischaemia in approximately 90% of the cases. In the years to come, it is to be expected that these endoluminal techniques will become the method of choice for treating most type-B dissections and will assist in significantly reducing the number of open surgical procedures required for type-A dissections. The intention of this article is to provide an overview of the current status of these endoluminal techniques based on our own experience as well as on a review of the relevant literature. (orig.)

  15. Left Ventricular Assist Device Implantation with Concomitant Aortic Valve and Ascending Aortic Replacement.

    Science.gov (United States)

    Huenges, Katharina; Panholzer, Bernd; Cremer, Jochen; Haneya, Assad

    2018-01-01

    Left ventricular assist device (LVAD) is nowadays a routine therapy for patients with advanced heart failure. We present the case of a 74-year-old male patient who was admitted to our center with terminal heart failure in dilated cardiomyopathy and ascending aortic aneurysm with aortic valve regurgitation. The LVAD implantation with simultaneous aortic valve and supracoronary ascending aortic replacement was successfully performed.

  16. Dynamics of the aortic annulus in 4D CT angiography for transcatheter aortic valve implantation patients

    NARCIS (Netherlands)

    Elattar, Mustafa A.; Vink, Leon W.; van Mourik, Martijn S.; Baan, Jan; Vanbavel, Ed T.; Planken, R. Nils; Marquering, Henk A.

    2017-01-01

    Transcatheter aortic valve implantation (TAVI) is a well-established treatment for patients with severe aortic valve stenosis. This procedure requires pre-operative planning by assessment of aortic dimensions on CT Angiography (CTA). It is well-known that the aortic root dimensions vary over the

  17. Bicuspid Aortic Valve Disease: A Comprehensive Review

    OpenAIRE

    Mordi, Ify; Tzemos, Nikolaos

    2012-01-01

    Bicuspid aortic valve is the commonest congenital cardiac abnormality in the general population. This paper article will discuss our current knowledge of the anatomy, pathophysiology, genetics, and clinical aspects of bicuspid aortic valve disease.

  18. Aortic compliance in patients with aortic regurgitation. Evaluation with magnetic resonance imaging

    International Nuclear Information System (INIS)

    Murai, Sachiko; Hamada, Seiki; Ueguchi, Takashi

    2005-01-01

    The purpose of this study was to assess by means of cine magnetic resonance imaging (MRI) aortic compliance before and after aortic valve replacement (AVR with SJM (St. Jude Medical, St paul, MN) valve) in patients with aortic regurgitation (AR). Two groups (healthy controls and patients with severe isolated AR) of 10 subjects each were included in this study. Cine MRI was performed at three locations of the aorta, and aortic compliance was calculated by dividing the maximum change in the aortic area by pulse pressure. Cine MRI is useful to assess abnormalities of aortic compliance in patients with AR. Compared with the control group, aortic compliance in the AR group was significantly less in the ascending aorta (p<0.05), decreasing in order of aortic location. After AVR, aortic compliance improved for all locations. Cine MRI enables assessment of aortic biophysical properties such as a compliance for evaluating the progression of AR and the efficacy of treatment. (author)

  19. Abdominal aortic feminism.

    Science.gov (United States)

    Mortimer, Alice Emily

    2014-11-14

    A 79-year-old woman presented to a private medical practice 2 years previously for an elective ultrasound screening scan. This imaging provided the evidence for a diagnosis of an abdominal aortic aneurysm (AAA) to be made. Despite having a number of recognised risk factors for an AAA, her general practitioner at the time did not follow the guidance set out by the private medical professional, that is, to refer the patient to a vascular specialist to be entered into a surveillance programme and surgically evaluated. The patient became symptomatic with her AAA, was admitted to hospital and found to have a tender, symptomatic, 6 cm leaking AAA. She consented for an emergency open AAA repair within a few hours of being admitted to hospital, despite the 50% perioperative mortality risk. The patient spent 4 days in intensive care where she recovered well. She was discharged after a 12 day hospital stay but unfortunately passed away shortly after her discharge from a previously undiagnosed gastric cancer. 2014 BMJ Publishing Group Ltd.

  20. Aortic atresia with normal sized left ventricle

    OpenAIRE

    Priya Jagia; Arun Sharma; Saurabh K Gupta; Munish Guleria

    2016-01-01

    Aortic atresia with an associated ventricular septal defect and adequate sized left ventricle is extremely rare. We present two cases in which an alternate diagnosis was suggested on echocardiography because the hypoplastic aortic trunk was missed due to its small caliber. The final diagnosis was, however, clinched on dual source computed tomography, which not only showed the thin aortic trunk but also clearly depicted the coronary artery origins from the hypoplastic aortic root. To the best ...

  1. A History of Thoracic Aortic Surgery.

    Science.gov (United States)

    McFadden, Paul Michael; Wiggins, Luke M; Boys, Joshua A

    2017-08-01

    Ancient historical texts describe the presence of aortic pathology conditions, although the surgical treatment of thoracic aortic disease remained insurmountable until the 19th century. Surgical treatment of thoracic aortic disease then progressed along with advances in surgical technique, conduit production, cardiopulmonary bypass, and endovascular technology. Despite radical advances in aortic surgery, principles established by surgical pioneers of the 19th century hold firm to this day. Copyright © 2017 Elsevier Inc. All rights reserved.

  2. Imaging findings in the right aortic arch with mirror image branching of arch vessels: An unusual cause of dysphagia

    Directory of Open Access Journals (Sweden)

    Guneet Singh

    2015-01-01

    Full Text Available We report a case of a 72-year-old female with a right aortic arch with mirror-image branching of arch vessels presenting with dysphagia, and characteristic images on barium esophagogram, contrast-enhanced computed tomography scan, and magnetic resonance aortography. Right-sided thoracic aortic arch with mirror-image branching of the brachiocephalic vessels causing dysphagia without associated congenital cardiac anomalies is extremely uncommon. Right-sided aortic arch is a rare congenital abnormality with incidence of 0.05-0.1% in the normal population. Anomalies of great vessels are usually incidental findings, because they are asymptomatic. Right aortic arch infrequently presents with a vascular ring that can cause complete or partial obstruction of the trachea and/or esophagus. The understanding of this arch anomaly is based on Edward′s hypothesis about the double arch system during embryonic developmental.

  3. Efecto vasodilatador mediado por óxido nítrico del extracto hidroalcohólico de Zea mays L. (maíz morado en anillos aórticos de rata Vasodilator effect mediated by nitric oxide of the Zea mays L (andean purple corn hydroalcoholic extract in aortic rings of rat

    Directory of Open Access Journals (Sweden)

    Oscar Moreno-Loaiza

    2010-12-01

    Full Text Available Objetivo. Evaluar la respuesta vasodilatadora e inhibidora de la vasoconstricción del extracto hidroalcohólico de Zea mays L. (maíz morado y determinar si esta respuesta es mediada por óxido nítrico (NO. Materiales y métodos. Se obtuvo un extracto de las corontas de maíz morado maceradas durante ocho días en etanol al 70%, y posterior concentración del producto. Se trabajó con anillos aórticos de rata en cámara de órganos aislados, bañada con solución Krebs-Hensleit (K-H y se registró la actividad vasomotora con un transductor de tensión isométrica. Se produjo una contracción basal con KCl 120 mM sobre la cual determinó el efecto vasodilatador de tres dosis del extracto: 0,1; 0,5 y 1,0 mg/mL. Se utilizó L-NG-Nitroarginina metil ester (L-NAME para comprobar que la vasodilatación depende de la óxido nítrico sinteasa (NOs. Luego se comparó la inhibición de la contracción vascular tras la incubación durante 30 minutos, con extracto de maíz morado y captopril 10-5 M. Resultados. Se observó una reducción de la contracción máxima (100% a 85,25 ± 2,60%, 77,76 ± 3,23% y 73,3 ± 4,87%, para las dosis de 0,1; 0,5 y 1,0 mg/mL, respectivamente. La vasodilatación fue inhibida por la incubación previa con L-NAME. El extracto de maíz morado no inhibió la contracción vascular, a diferencia del captopril (reducción a 75,27 ± 8,61%. Conclusión. El extracto hidroalcohólico de Zea mays L produce vasodilatación dependiente de la síntesis de NO.Objective: To evaluate the vasodilator response of the hydroalcoholic extract of Zea mays L. (Andean purple corn and to determine if this response is mediated by nitric oxide (NO. Material and methods: We obtained an extract by maceration for eight days of Andean purple corn cobs in 70% ethanol and subsequent concentration of the product. Thoracic aortic rings were evaluated in an isolated organ chamber, bathed with Krebs-Hensleit solution (KH, and vasomotor activity was recorded

  4. Aortic or Mitral Valve Replacement With the Biocor and Biocor Supra

    Science.gov (United States)

    2017-04-26

    Aortic Valve Insufficiency; Aortic Valve Regurgitation; Aortic Valve Stenosis; Aortic Valve Incompetence; Mitral Valve Insufficiency; Mitral Valve Regurgitation; Mitral Valve Stenosis; Mitral Valve Incompetence

  5. Thoracic Endovascular Aortic Repair (TEVAR) in Proximal (Type A) Aortic Dissection: Ready for a Broader Application?

    OpenAIRE

    Nienaber, Christoph A.; Sakalihasan, Natzi; Clough, Rachel E.; Aboukoura, Mohamed; Mancuso, Enrico; Yeh, James S.M.; Defraigne, Jean-Olivier; Cheshire, Nick; Rosendahl, Ulrich Peter; Quarto, Cesare; Pepper, John

    2016-01-01

    ObjectiveThoracic endovascular aortic repair (TEVAR) has demonstrated encouraging results and is gaining increasing acceptance as a treatment option for aortic aneurysms and dissections. Yet, its role in managing proximal aortic pathologies is unknown - this is important because in proximal (Stanford type A) aortic dissections, 10-30% are not accepted for surgery, and 30-50% are technically amenable for TEVAR. We describe our case series of type A aortic dissections treated using TEVAR.Method...

  6. Rings in drugs.

    Science.gov (United States)

    Taylor, Richard D; MacCoss, Malcolm; Lawson, Alastair D G

    2014-07-24

    We have analyzed the rings, ring systems, and frameworks in drugs listed in the FDA Orange Book to understand the frequency, timelines, molecular property space, and the application of these rings in different therapeutic areas and target classes. This analysis shows that there are only 351 ring systems and 1197 frameworks in drugs that came onto the market before 2013. Furthermore, on average six new ring systems enter drug space each year and approximately 28% of new drugs contain a new ring system. Moreover, it is very unusual for a drug to contain more than one new ring system and the majority of the most frequently used ring systems (83%) were first used in drugs developed prior to 1983. These observations give insight into the chemical novelty of drugs and potentially efficient ways to assess compound libraries and develop compounds from hit identification to lead optimization and beyond.

  7. Birth Control Ring

    Science.gov (United States)

    ... Health Food & Fitness Diseases & Conditions Infections Drugs & Alcohol School & Jobs Sports Expert Answers (Q&A) Staying Safe Videos for Educators Search English Español Birth Control Ring KidsHealth / For Teens / Birth Control Ring What's ...

  8. Oesophageal foreign body and a double aortic arch: rare dual pathology.

    Science.gov (United States)

    O'Connor, T E; Cooney, T

    2009-12-01

    We report the rare case of an oesophageal foreign body which lodged above the site of oesophageal compression by a double aortic arch. Case report and a review of the literature surrounding the classification, embryology, diagnosis and management of vascular rings and slings. An eight-month-old male infant presented with symptoms of tracheal compression following ingestion of an oesophageal foreign body. Following removal of the oesophageal foreign body, the infant's symptoms improved initially. However, subsequent recurrence of respiratory symptoms lead to a repeat bronchoscopy and the diagnosis of a coexisting double aortic arch, causing tracheal and oesophageal compression. To our knowledge, this is only the second reported case of a double aortic arch being diagnosed in a patient following removal of an oesophageal foreign body.

  9. Groups, rings, modules

    CERN Document Server

    Auslander, Maurice

    2014-01-01

    This classic monograph is geared toward advanced undergraduates and graduate students. The treatment presupposes some familiarity with sets, groups, rings, and vector spaces. The four-part approach begins with examinations of sets and maps, monoids and groups, categories, and rings. The second part explores unique factorization domains, general module theory, semisimple rings and modules, and Artinian rings. Part three's topics include localization and tensor products, principal ideal domains, and applications of fundamental theorem. The fourth and final part covers algebraic field extensions

  10. Evolution of the Proximal Sealing Rings of the Anaconda Stent-Graft After Endovascular Aneurysm Repair

    NARCIS (Netherlands)

    Koenrades, Maaike A.; Klein, Almar; Leferink, Anne M.; Slump, Cornelis H.; Geelkerken, Robert H.

    2018-01-01

    Purpose: To provide insight into the evolution of the saddle-shaped proximal sealing rings of the Anaconda stent-graft after endovascular aneurysm repair (EVAR). Methods: Eighteen abdominal aortic aneurysm patients were consecutively enrolled in a single-center, prospective, observational cohort

  11. [Bacteremia associated with mycotic aneurysm of the transversal aortic arch and myocarditis caused by Salmonella enteritidis].

    Science.gov (United States)

    Martínez-Martínez, L; Mesa, E; Rodríguez, J E; Sánchez, M P; Ugarte, J; Algora Weber, A; Dámaso, D; Daza, R M; Mendaza, P

    1989-02-01

    A 60-year-old male with diabetes mellitus had Salmonella enteritidis bacteremia associated with mycotic aneurysm of the transverse aortic arc and myocarditis. Antibiotic therapy with ampicillin and chloramphenicol was ineffective despite the fact that the microorganism was sensitive in vitro to those antimicrobials, and the patient had a progressive clinical deterioration which culminated in death.

  12. Aortic atresia with normal sized left ventricle

    Directory of Open Access Journals (Sweden)

    Priya Jagia

    2016-01-01

    Full Text Available Aortic atresia with an associated ventricular septal defect and adequate sized left ventricle is extremely rare. We present two cases in which an alternate diagnosis was suggested on echocardiography because the hypoplastic aortic trunk was missed due to its small caliber. The final diagnosis was, however, clinched on dual source computed tomography, which not only showed the thin aortic trunk but also clearly depicted the coronary artery origins from the hypoplastic aortic root. To the best of our knowledge, use of multi-detector computed tomography in aortic atresia with well developed left ventricle has not been reported in literature till date.

  13. MMP-2 Isoforms in Aortic Tissue and Serum of Patients with Ascending Aortic Aneurysms and Aortic Root Aneurysms

    Science.gov (United States)

    Tscheuschler, Anke; Meffert, Philipp; Beyersdorf, Friedhelm; Heilmann, Claudia; Kocher, Nadja; Uffelmann, Xenia; Discher, Philipp; Siepe, Matthias; Kari, Fabian A.

    2016-01-01

    Objective The need for biological markers of aortic wall stress and risk of rupture or dissection of ascending aortic aneurysms is obvious. To date, wall stress cannot be related to a certain biological marker. We analyzed aortic tissue and serum for the presence of different MMP-2 isoforms to find a connection between serum and tissue MMP-2 and to evaluate the potential of different MMP-2 isoforms as markers of high wall stress. Methods Serum and aortic tissue from n = 24 patients and serum from n = 19 healthy controls was analyzed by ELISA and gelatin zymography. 24 patients had ascending aortic aneurysms, 10 of them also had aortic root aneurysms. Three patients had normally functioning valves, 12 had regurgitation alone, eight had regurgitation and stenosis and one had only stenosis. Patients had bicuspid and tricuspid aortic valves (9/15). Serum samples were taken preoperatively, and the aortic wall specimen collected during surgical aortic repair. Results Pro-MMP-2 was identified in all serum and tissue samples. Pro-MMP-2 was detected in all tissue and serum samples from patients with ascending aortic/aortic root aneurysms, irrespective of valve morphology or other clinical parameters and in serum from healthy controls. We also identified active MMP-2 in all tissue samples from patients with ascending aortic/aortic root aneurysms. None of the analyzed serum samples revealed signals relatable to active MMP-2. No correlation between aortic tissue total MMP-2 or tissue pro-MMP-2 or tissue active MMP-2 and serum MMP-2 was found and tissue MMP-2/pro-MMP-2/active MMP-2 did not correlate with aortic diameter. This evidence shows that pro-MMP-2 is the predominant MMP-2 species in serum of patients and healthy individuals and in aneurysmatic aortic tissue, irrespective of aortic valve configuration. Active MMP-2 species are either not released into systemic circulation or not detectable in serum. There is no reliable connection between aortic tissue—and serum MMP-2

  14. Strain measurement of abdominal aortic aneurysm with real-time 3D ultrasound speckle tracking.

    Science.gov (United States)

    Bihari, P; Shelke, A; Nwe, T H; Mularczyk, M; Nelson, K; Schmandra, T; Knez, P; Schmitz-Rixen, T

    2013-04-01

    Abdominal aortic aneurysm rupture is caused by mechanical vascular tissue failure. Although mechanical properties within the aneurysm vary, currently available ultrasound methods assess only one cross-sectional segment of the aorta. This study aims to establish real-time 3-dimensional (3D) speckle tracking ultrasound to explore local displacement and strain parameters of the whole abdominal aortic aneurysm. Validation was performed on a silicone aneurysm model, perfused in a pulsatile artificial circulatory system. Wall motion of the silicone model was measured simultaneously with a commercial real-time 3D speckle tracking ultrasound system and either with laser-scan micrometry or with video photogrammetry. After validation, 3D ultrasound data were collected from abdominal aortic aneurysms of five patients and displacement and strain parameters were analysed. Displacement parameters measured in vitro by 3D ultrasound and laser scan micrometer or video analysis were significantly correlated at pulse pressures between 40 and 80 mmHg. Strong local differences in displacement and strain were identified within the aortic aneurysms of patients. Local wall strain of the whole abdominal aortic aneurysm can be analysed in vivo with real-time 3D ultrasound speckle tracking imaging, offering the prospect of individual non-invasive rupture risk analysis of abdominal aortic aneurysms. Copyright © 2013 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved.

  15. Management of an elderly patient with respiratory failure due to double aortic arch

    Directory of Open Access Journals (Sweden)

    Changwan Ryu

    2016-01-01

    Full Text Available Vascular rings are congenital malformations of the aortic arch. A double aortic arch (DAA, the most common type of vascular ring, results from the failure of the fourth embryonic branchial arch to regress, leading to an ascending aorta that divides into a left and right arch that fuse together to completely encircle the trachea and esophagus. The subsequent DAA causes compressive effects on the trachea and esophagus that typically manifests in infancy or early childhood. Adult presentations, particularly in the elderly, are exceedingly rare. Historically such patients have a long-standing history of dyspnea on exertion and dysphagia, with many assumed to have obstructive lung or intrinsic cardiac disease. We describe a case of an elderly woman who presented with respiratory failure due to DAA. In her case, surgery was not feasible and we describe our experience with airway stenting.

  16. Aortic Root Enlargement or Sutureless Valve Implantation?

    Directory of Open Access Journals (Sweden)

    Nikolaos G. Baikoussis

    2016-11-01

    Full Text Available Aortic valve replacement (AVR in patients with a small aortic annulus is a challenging issue. The importance of prosthesis–patient mismatch (PPM post aortic valve replacement (AVR is controversial but has to be avoided. Many studies support the fact that PPM has a negative impact on short and long term survival. In order to avoid PPM, aortic root enlargement may be performed. Alternatively and keeping in mind that often some comorbidities are present in old patients with small aortic root, the Perceval S suturelles valve implantation could be a perfect solution. The Perceval sutureless bioprosthesis provides reasonable hemodynamic performance avoiding the PPM and providing the maximum of aortic orifice area. We would like to see in the near future the role of the aortic root enlargement techniques in the era of surgical implantation of the sutureless valve (SAVR and the transcatheter valve implantation (TAVI.

  17. Aortic valve function after bicuspidization of the unicuspid aortic valve.

    Science.gov (United States)

    Aicher, Diana; Bewarder, Moritz; Kindermann, Michael; Abdul-Khalique, Hashim; Schäfers, Hans-Joachim

    2013-05-01

    Unicuspid aortic valve (UAV) anatomy leads to dysfunction of the valve in young individuals. We introduced a reconstructive technique of bicuspidizing the UAV. Initially we copied the typical asymmetry of a normal bicuspid aortic valve (BAV) (I), later we created a symmetric BAV (II). This study compared the hemodynamic function of the two designs of a bicuspidized UAV. Aortic valve function was studied at rest and during exercise in 28 patients after repair of UAV (group I, n = 8; group II, n = 20). There were no differences among the groups I and II with respect to gender, age, body size, or weight. All patients were in New York Heart Association class I. Six healthy adults served as control individuals. All patients were studied with transthoracic echocardiography between 4 and 65 months postoperatively. Systolic gradients were assessed by continuous wave Doppler while patients were at rest and exercising on a bicycle ergometer. Aortic regurgitation was grade I or less in all patients. Resting gradients were significantly elevated in group I compared with group II and control individuals (group I, peak 33.8 ± 7.8 mm Hg; mean 19.1 ± 5.4 mm Hg; group II, peak 15.8 ± 5.4, mean 8.2 ± 2.8 mm Hg; control individuals, peak 6.0 ± 1.6, mean 3.2 ± 0.8 mm Hg; p competence. A symmetric repair design leads to improved systolic aortic valve function at rest and during exercise. Copyright © 2013 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

  18. Possible mechanisms involved in the vasorelaxant effect produced by clobenzorex in aortic segments of rats

    OpenAIRE

    Lozano-Cuenca, J.; González-Hernández, A.; López-Canales, O.A.; Villagrana-Zesati, J.R.; Rodríguez-Choreão, J.D.; Morín-Zaragoza, R.; Castillo-Henkel, E.F.; López-Canales, J.S.

    2017-01-01

    Clobenzorex is a metabolic precursor of amphetamine indicated for the treatment of obesity. Amphetamines have been involved with cardiovascular side effects such as hypertension and pulmonary arterial hypertension. The aim of the present study was to investigate whether the direct application of 10?9?10?5 M clobenzorex on isolated phenylephrine-precontracted rat aortic rings produces vascular effects, and if so, what mechanisms may be involved. Clobenzorex produced an immediate concentration-...

  19. Transcatheter valve-in-valve implantation due to severe aortic regurgitation in a degenerated aortic homograft

    DEFF Research Database (Denmark)

    Olsen, Lene Kjaer; Engstrøm, Thomas; Søndergaard, Lars

    2009-01-01

    Transcatheter aortic valve implantation (TAVI) in severe aortic stenosis has proven to be a feasible and effective treatment modality for inoperable patients. Until now, neither aortic regurgitation nor degenerated bioprostheses has been an indication for TAVI. However, this article reports...... a successful valve-in-valve implantation of a CoreValve aortic valve prosthesis through the right subclavian artery in a case of severe aortic regurgitation within a degenerated aortic homograft. The case exemplifies the possibilities of expanding the indications for TAVI, as well as other vascular access...

  20. Statins for aortic valve stenosis

    Directory of Open Access Journals (Sweden)

    Luciana Thiago

    Full Text Available ABSTRACT BACKGROUND: Aortic valve stenosis is the most common type of valvular heart disease in the USA and Europe. Aortic valve stenosis is considered similar to atherosclerotic disease. Some studies have evaluated statins for aortic valve stenosis. OBJECTIVES: To evaluate the effectiveness and safety of statins in aortic valve stenosis. METHODS: Search methods: We searched the Cochrane Central Register of Controlled Trials (CENTRAL, MEDLINE, Embase, LILACS - IBECS, Web of Science and CINAHL Plus. These databases were searched from their inception to 24 November 2015. We also searched trials in registers for ongoing trials. We used no language restrictions. Selection criteria: Randomized controlled clinical trials (RCTs comparing statins alone or in association with other systemic drugs to reduce cholesterol levels versus placebo or usual care. Data collection and analysis: Primary outcomes were severity of aortic valve stenosis (evaluated by echocardiographic criteria: mean pressure gradient, valve area and aortic jet velocity, freedom from valve replacement and death from cardiovascular cause. Secondary outcomes were hospitalization for any reason, overall mortality, adverse events and patient quality of life. Two review authors independently selected trials for inclusion, extracted data and assessed the risk of bias. The GRADE methodology was employed to assess the quality of result findings and the GRADE profiler (GRADEPRO was used to import data from Review Manager 5.3 to create a 'Summary of findings' table. MAIN RESULTS: We included four RCTs with 2360 participants comparing statins (1185 participants with placebo (1175 participants. We found low-quality evidence for our primary outcome of severity of aortic valve stenosis, evaluated by mean pressure gradient (mean difference (MD -0.54, 95% confidence interval (CI -1.88 to 0.80; participants = 1935; studies = 2, valve area (MD -0.07, 95% CI -0.28 to 0.14; participants = 127; studies = 2

  1. Statins for aortic valve stenosis.

    Science.gov (United States)

    Thiago, Luciana; Tsuji, Selma Rumiko; Nyong, Jonathan; Puga, Maria Eduarda Dos Santos; Góis, Aécio Flávio Teixeira de; Macedo, Cristiane Rufino; Valente, Orsine; Atallah, Álvaro Nagib

    2016-01-01

    Aortic valve stenosis is the most common type of valvular heart disease in the USA and Europe. Aortic valve stenosis is considered similar to atherosclerotic disease. Some studies have evaluated statins for aortic valve stenosis. To evaluate the effectiveness and safety of statins in aortic valve stenosis. Search methods: We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, LILACS - IBECS, Web of Science and CINAHL Plus. These databases were searched from their inception to 24 November 2015. We also searched trials in registers for ongoing trials. We used no language restrictions.Selection criteria: Randomized controlled clinical trials (RCTs) comparing statins alone or in association with other systemic drugs to reduce cholesterol levels versus placebo or usual care. Data collection and analysis: Primary outcomes were severity of aortic valve stenosis (evaluated by echocardiographic criteria: mean pressure gradient, valve area and aortic jet velocity), freedom from valve replacement and death from cardiovascular cause. Secondary outcomes were hospitalization for any reason, overall mortality, adverse events and patient quality of life.Two review authors independently selected trials for inclusion, extracted data and assessed the risk of bias. The GRADE methodology was employed to assess the quality of result findings and the GRADE profiler (GRADEPRO) was used to import data from Review Manager 5.3 to create a 'Summary of findings' table. We included four RCTs with 2360 participants comparing statins (1185 participants) with placebo (1175 participants). We found low-quality evidence for our primary outcome of severity of aortic valve stenosis, evaluated by mean pressure gradient (mean difference (MD) -0.54, 95% confidence interval (CI) -1.88 to 0.80; participants = 1935; studies = 2), valve area (MD -0.07, 95% CI -0.28 to 0.14; participants = 127; studies = 2), and aortic jet velocity (MD -0.06, 95% CI -0.26 to 0

  2. Aortic intramural hematoma : assessment of clinical and radiological features in comparison to acute aortic dissection

    International Nuclear Information System (INIS)

    Yoon, Kwon Ha; Hwang, Jae Cheol; Lee, Jin Seong; Kang, Duk Hyun; Song, Jae Kwan; Song, Koun Sik; Lim, Tae Hwan

    1996-01-01

    To compare the clinical and radiological features of aortic intramural hematoma(IMH) to those of acute aortic dissection(AD). We analyzed the clinical and radiological features of 12 patients with aortic IMH and 43 patients with acute AD. In aortic IMH, the diagnoses were made by means of both CT and transesophageal echocardiography(TEE) and included two surgically proven cases. In acute AD, the diagnoses were made by means of CT and TEE and included 21 surgically proven cases. We compared patients ages, etiologies, the extent of the disease, the presence or absence of aortic branch involvement, complications, and outcomes. Aortic IMH tended to develop in older patients (67.8±7.9 vs. 50.4±13.4, P .05). In aortic IMH, there was no involvement of aortic branches, whereas in acute AD, 14(33%) patients showed involvement of one or more aortic branches. Complications of aortic IMH included pericardial effusion (n=2) and pleural effusion (n=4);in acute AD, pericardial effusion (n=7), pleural effusion (n=4), aortic insufficiency (n=8), cerebral infarction (n=3), renal infarction (n=4) and spinal infarction (n=1) were seen. There was one (8%) death due to aortic IMH and ten (23%) deaths due to acute AD (p<.01). Aortic IMH is characterized by its occurrence in older patients with hypertension, a less frequent incidence of complications, and a more favorable outcome than acute AD

  3. Decreased expression of fibulin-4 in aortic wall of aortic dissection.

    Science.gov (United States)

    Huawei, P; Qian, C; Chuan, T; Lei, L; Laing, W; Wenlong, X; Wenzhi, L

    2014-02-01

    In this research, we will examine the expression of Fibulin-4 in aortic wall to find out its role in aortic dissection development. The samples of aortic wall were obtained from 10 patients operated for acute ascending aortic dissection and five patients for chronic ascending aortic dissection. Another 15 pieces of samples from patients who had coronary artery bypass were as controls. The aortic samples were stained with aldehyde magenta dyeing to evaluate the arrangement of elastic fibers. The Fibulin-4 protein and mRNA expression were both determined by Western blot and realtime quantitative polymerase chain reaction. Compared with the control group, both in acute and chronic ascending aortic dissection, elastic fiber fragments increased and the expression of fibulin-4 protein significantly decreased (P= 0.045 < 0.05). The level of fibulin-4 mRNA decreased in acute ascending aortic dissection (P= 0.034 < 0.05), while it increased in chronic ascending aortic dissection (P=0.004 < 0.05). The increased amounts of elastic fiber fragments were negatively correlated with the expression of fibulin-4 mRNA in acute ascending aortic dissection. In conclusion, in aortic wall of ascending aortic dissection, the expression of fibulin-4 protein decreased and the expression of fibulin-4 mRNA was abnormal. Fibulin-4 may play an important role in the pathogenesis of aortic dissection.

  4. Molecular and cellular mechanisms of aortic stenosis.

    Science.gov (United States)

    Yetkin, Ertan; Waltenberger, Johannes

    2009-06-12

    Calcific aortic stenosis is the most common cause of aortic valve replacement in developed countries, and this condition increases in prevalence with advancing age. The fibrotic thickening and calcification are common eventual endpoint in both non-rheumatic calcific and rheumatic aortic stenoses. New observations in human aortic valves support the hypothesis that degenerative valvular aortic stenosis is the result of active bone formation in the aortic valve, which may be mediated through a process of osteoblast-like differentiation in these tissues. Additionally histopathologic evidence suggests that early lesions in aortic valves are not just a disease process secondary to aging, but an active cellular process that follows the classical "response to injury hypothesis" similar to the situation in atherosclerosis. Although there are similarities with the risk factor and as well as with the process of atherogenesis, not all the patients with coronary artery disease or atherosclerosis have calcific aortic stenosis. This review mainly focuses on the potential vascular and molecular mechanisms involved in the pathogenesis of aortic valve stenosis. Namely extracellular matrix remodeling, angiogenesis, inflammation, and eventually osteoblast-like differentiation resulting in bone formation have been shown to play a role in the pathogenesis of calcific aortic stenosis. Several mediators related to underlying mechanisms, including growth factors especially transforming growth factor-beta1 and vascular endothelial growth factors, angiogenesis, cathepsin enzymes, adhesion molecules, bone regulatory proteins and matrix metalloproteinases have been demonstrated, however the target to be attacked is not defined yet.

  5. Token Ring Project

    Directory of Open Access Journals (Sweden)

    Adela Ionescu

    2007-01-01

    Full Text Available Ring topology is a simple configuration used to connect processes that communicate among themselves. A number of network standards such as token ring, token bus, and FDDI are based on the ring connectivity. This article will develop an implementation of a ring of processes that communicate among themselves via pipe links. The processes are nodes in the ring. Each process reads from its standard input and writes in its standard output. N-1 process redirects the its standard output to a standard input of the process through a pipe. When the ring-structure is designed, the project can be extended to simulate networks or to implement algorithms for mutual exclusion

  6. Token ring technology report

    CERN Document Server

    2013-01-01

    Please note this is a Short Discount publication. This report provides an overview of the IBM Token-Ring technology and products built by IBM and compatible vendors. It consists of two sections: 1. A summary of the design trade-offs for the IBM Token-Ring. 2. A summary of the products of the major token-ring compatible vendors broken down by adapters and components, wiring systems, testing, and new chip technology.

  7. Radioactive gold ring dermatitis

    International Nuclear Information System (INIS)

    Miller, R.A.; Aldrich, J.E.

    1990-01-01

    A superficial squamous cell carcinoma developed in a woman who wore a radioactive gold ring for more than 30 years. Only part of the ring was radioactive. Radiation dose measurements indicated that the dose to basal skin layer was 2.4 Gy (240 rad) per week. If it is assumed that the woman continually wore her wedding ring for 37 years since purchase, she would have received a maximum dose of approximately 4600 Gy

  8. Vascular ring presenting as dysphagia in an adult woman: a case report.

    Science.gov (United States)

    Powell, B L

    2017-01-01

    A 48-year-old woman was seen in a surgical outpatient clinic with a 2 year history of progressive dysphagia with occasional regurgitation, partially controlled with a proton pump inhibitor. Primary investigations of pH testing and gastroscopy were normal, although a barium swallow study revealed significant hold-up at the aortic arch impression and a posterior right-sided oesophageal impression suggestive of a right-sided aortic arch. A follow-up computed tomography angiogram discovered a vascular ring encircling the trachea and oesophagus, formed by a right-sided aortic arch with aberrant aortic branches, and a Kommerell's diverticulum. It was deemed that the patient's symptoms were related to this vascular ring. The patient underwent stage-one surgery - an extra-anatomic bypass of the double aortic arch and right subclavian artery - and 4 months later a stent graft insertion over the origin of the diverticulum with the aim of complete symptomatic relief. This case presents a common symptom familiar to any clinician (dysphagia), which has been caused by a rare pathology. It is even more unusual that this should present itself in adulthood.

  9. Physics of quantum rings

    International Nuclear Information System (INIS)

    Fomin, Vladimir M.

    2014-01-01

    Presents the new class of materials of quantum rings. Provides an elemental basis for low-cost high-performance devices promising for electronics, optoelectronics, spintronics and quantum information processing. Explains the physical properties of quantum rings to cover a gap in scientific literature. Presents the application of most advanced nanoengineering and nanocharacterization techniques. This book deals with a new class of materials, quantum rings. Innovative recent advances in experimental and theoretical physics of quantum rings are based on the most advanced state-of-the-art fabrication and characterization techniques as well as theoretical methods. The experimental efforts allow to obtain a new class of semiconductor quantum rings formed by capping self-organized quantum dots grown by molecular beam epitaxy. Novel optical and magnetic properties of quantum rings are associated with non-trivial topologies at the nanoscale. An adequate characterization of quantum rings is possible on the basis of modern characterization methods of nanostructures, such as Scanning Tunneling Microscopy. A high level of complexity is demonstrated to be needed for a dedicated theoretical model to adequately represent the specific features of quantum rings. The findings presented in this book contribute to develop low-cost high-performance electronic, spintronic, optoelectronic and information processing devices based on quantum rings.

  10. Aorto-aortic intrathoracic bypass in surgical treatment of aortic

    International Nuclear Information System (INIS)

    Gutierrez Perez, F.; Duran Reyes, A.; Bigalli, D.; Filgueira Berobide, J.

    1998-01-01

    The prevalence of coarctation of the aorta is 6.5 percent of all congenital heart defects, according to national and international data. There is a restenosis rate of patients after surgery. Factors that influence this evolution depends on the age at which patients underwent surgery for the first time the anatomy of the aortic arch and type of surgical technique. Several procedures can be used to correct the coarctation, which include surgery and balloon catheter dilation. We present here a case of a patient of 22 years old, with a recurrent coarctation of the aorta studied by echocardiography and magnetic resonance imaging. The patient underwent surgery a third time. We used an anterior approach (median sternotomy) and performed an aortic bypass graft, intrathoracic, under cardiopulmonary bypass. Evolved favorably and was discharged on the sixth day of post operative day (Author) [es

  11. Aortic root geometry in aortic stenosis patients (a SEAS substudy)

    DEFF Research Database (Denmark)

    Bahlmann, Edda; Nienaber, Christoph A; Cramariuc, Dana

    2011-01-01

    -specified requirements for the aortic root geometry for current available prostheses, CoreValve and Edwards-Sapien. The ratio of sinus of Valsalva height to sinus width was 1:2. In multivariate linear regression analysis, larger sinus of Valsalva height was associated with older age, larger sinus of Valsalva diameter......, lower ejection fraction and smaller supracoronary diameter (multiple R(2) = 0.19, PSapien prosthesis in 66.9%. Overall, annular dimension feasible for TAVI using any available prosthesis was found...

  12. In vitro vascular effects produced by crude aqueous extract of green marine algae, Cladophora patentiramea (Mont.) Kützing, in aorta from normotensive rats.

    Science.gov (United States)

    Lim, Yee-Ling; Mok, Shiueh-Lian

    2010-01-01

    To investigate the antihypertensive activity of aqueous extracts obtained from Malaysian coastal seaweeds and to determine the pharmacological mechanisms of the extracts on rat aorta in vitro. The antihypertensive activity of 11 species of seaweeds (5 brown, 1 red and 5 green algae) were tested by cumulative addition of the extracts to phenylephrine (PE)-precontracted Wistar-Kyoto (WKY) aortic rings in in vitro isometric contraction studies. Mechanisms for vasorelaxant effect were investigated in the presence of various antagonists. Of the 11 species tested, 2 showed a vasorelaxant effect. Further investigation of the mechanisms of action of the aqueous extract of green alga, Cladophora patentiramea (AECP),showed that the vascular relaxant effect was endothelium- and concentration-dependent. A maximum relaxation of 45.8 +/- 4.6% (n = 8, p < 0.001) was obtained at 0.1 mg/ml of extract, after which the response was found to reduce in a concentration-dependent manner to 15.7 +/- 4.9% (n = 8, p < 0.001) at the highest extract concentration tested. Pretreatment of endothelium-intact aortic rings with Nomega-nitro-L-arginine methyl ester (L-NAME, 30 microM), (1)H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ, 10 microM) and methylene blue (100 microM) resulted in a complete blockade of AECP-induced vasorelaxation. However, the relaxant effects of the extract were not blocked by atropine (1 microM), indomethacin (10 microM) and glibenclamide (10 microM), although the maximum relaxant responses were enhanced in the presence of glibenclamide. Our data showed that the in vitro vascular relaxant effect of AECPwas mediated through endothelium-dependent nitric oxide-cGMP pathway, and was not associated with the release of vasodilator prostaglandins, activation of muscarinic receptors, or ATP-sensitive potassium channels opening. Copyright 2010 S. Karger AG, Basel.

  13. The cardiovascular effects of aortic clamping and unclamping

    African Journals Online (AJOL)

    aortic clamping is that afterload and blood pressure increase, and ... individually, albeit they interact with each other. The degree of ... position of the aortic clamp, the greater the increase ... the increase in preload in response to aortic clamping.

  14. Indexing aortic valve area by body surface area increases the prevalence of severe aortic stenosis

    DEFF Research Database (Denmark)

    Jander, Nikolaus; Gohlke-Bärwolf, Christa; Bahlmann, Edda

    2014-01-01

    To account for differences in body size in patients with aortic stenosis, aortic valve area (AVA) is divided by body surface area (BSA) to calculate indexed AVA (AVAindex). Cut-off values for severe stenosis are......To account for differences in body size in patients with aortic stenosis, aortic valve area (AVA) is divided by body surface area (BSA) to calculate indexed AVA (AVAindex). Cut-off values for severe stenosis are...

  15. Aortic valvuloplasty of calcific aortic stenosis with monofoil and trefoil balloon catheters: practical considerations

    NARCIS (Netherlands)

    S. Plante (Sylvain); M.J.B.M. van den Brand (Marcel); L.C.P. van Veen; C. di Mario (Carlo); C.E. Essed; K.J. Beatt (Kevin); P.W.J.C. Serruys (Patrick)

    1990-01-01

    textabstractIn order to evaluate the relation between balloon design (monofoil, trefoil) and valvular configuration, experimental aortic valvuloplasty was performed in four post-mortem hearts with calcific aortic stenosis of various morphology. The degree of obstruction of the aortic orifice was

  16. Association Between Gout and Aortic Stenosis.

    Science.gov (United States)

    Chang, Kevin; Yokose, Chio; Tenner, Craig; Oh, Cheongeun; Donnino, Robert; Choy-Shan, Alana; Pike, Virginia C; Shah, Binita D; Lorin, Jeffrey D; Krasnokutsky, Svetlana; Sedlis, Steven P; Pillinger, Michael H

    2017-02-01

    An independent association between gout and coronary artery disease is well established. The relationship between gout and valvular heart disease, however, is unclear. The aim of this study was to assess the association between gout and aortic stenosis. We performed a retrospective case-control study. Aortic stenosis cases were identified through a review of outpatient transthoracic echocardiography (TTE) reports. Age-matched controls were randomly selected from patients who had undergone TTE and did not have aortic stenosis. Charts were reviewed to identify diagnoses of gout and the earliest dates of gout and aortic stenosis diagnosis. Among 1085 patients who underwent TTE, 112 aortic stenosis cases were identified. Cases and nonaortic stenosis controls (n = 224) were similar in age and cardiovascular comorbidities. A history of gout was present in 21.4% (n = 24) of aortic stenosis subjects compared with 12.5% (n = 28) of controls (unadjusted odds ratio 1.90, 95% confidence interval 1.05-3.48, P = .038). Multivariate analysis retained significance only for gout (adjusted odds ratio 2.08, 95% confidence interval 1.00-4.32, P = .049). Among subjects with aortic stenosis and gout, gout diagnosis preceded aortic stenosis diagnosis by 5.8 ± 1.6 years. The age at onset of aortic stenosis was similar among patients with and without gout (78.7 ± 1.8 vs 75.8 ± 1.0 years old, P = .16). Aortic stenosis patients had a markedly higher prevalence of precedent gout than age-matched controls. Whether gout is a marker of, or a risk factor for, the development of aortic stenosis remains uncertain. Studies investigating the potential role of gout in the pathophysiology of aortic stenosis are warranted and could have therapeutic implications. Published by Elsevier Inc.

  17. Low-gradient aortic stenosis.

    Science.gov (United States)

    Clavel, Marie-Annick; Magne, Julien; Pibarot, Philippe

    2016-09-07

    An important proportion of patients with aortic stenosis (AS) have a 'low-gradient' AS, i.e. a small aortic valve area (AVA gradient (gradient discrepancy raises uncertainty about the actual stenosis severity and thus about the indication for aortic valve replacement (AVR) if the patient has symptoms and/or left ventricular (LV) systolic dysfunction. The most frequent cause of low-gradient (LG) AS is the presence of a low LV outflow state, which may occur with reduced left ventricular ejection fraction (LVEF), i.e. classical low-flow, low-gradient (LF-LG), or preserved LVEF, i.e. paradoxical LF-LG. Furthermore, a substantial proportion of patients with AS may have a normal-flow, low-gradient (NF-LG) AS: i.e. a small AVA-low-gradient combination but with a normal flow. One of the most important clinical challenges in these three categories of patients with LG AS (classical LF-LG, paradoxical LF-LG, and NF-LG) is to differentiate a true-severe AS that generally benefits from AVR vs. a pseudo-severe AS that should be managed conservatively. A low-dose dobutamine stress echocardiography may be used for this purpose in patients with classical LF-LG AS, whereas aortic valve calcium scoring by multi-detector computed tomography is the preferred modality in those with paradoxical LF-LG or NF-LG AS. Although patients with LF-LG severe AS have worse outcomes than those with high-gradient AS following AVR, they nonetheless display an important survival benefit with this intervention. Some studies suggest that transcatheter AVR may be superior to surgical AVR in patients with LF-LG AS. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2016. For permissions please email: journals.permissions@oup.com.

  18. EBT ring physics

    International Nuclear Information System (INIS)

    Uckan, N.A.

    1980-04-01

    This workshop attempted to evaluate the status of the current experimental and theoretical understanding of hot electron ring properties. The dominant physical processes that influence ring formation, scaling, and their optimal behavior are also studied. Separate abstracts were prepared for each of the 27 included papers

  19. Thoracic aortic aneurysms and dissections: endovascular treatment.

    Science.gov (United States)

    Baril, Donald T; Cho, Jae S; Chaer, Rabih A; Makaroun, Michel S

    2010-01-01

    The treatment of thoracic aortic disease has changed radically with the advances made in endovascular therapy since the concept of thoracic endovascular aortic repair was first described 15 years ago. Currently, there is a diverse array of endografts that are commercially available to treat the thoracic aorta. Multiple studies, including industry-sponsored and single-institution reports, have demonstrated excellent outcomes of thoracic endovascular aortic repair for the treatment of thoracic aortic aneurysms, with less reported perioperative morbidity and mortality in comparison with conventional open repair. Additionally, similar outcomes have been demonstrated for the treatment of type B dissections. However, the technology remains relatively novel, and larger studies with longer term outcomes are necessary to more fully evaluate the role of endovascular therapy for the treatment of thoracic aortic disease. This review examines the currently available thoracic endografts, preoperative planning for thoracic endovascular aortic repair, and outcomes of thoracic endovascular aortic repair for the treatment of both thoracic aortic aneurysms and type B aortic dissections. Mt Sinai J Med 77:256-269, 2010. (c) 2010 Mount Sinai School of Medicine.

  20. Hybrid treatment of penetrating aortic ulcer

    International Nuclear Information System (INIS)

    Lara, Juan Antonio Herrero; Martins-Romeo, Daniela de Araujo; Escudero, Carlos Caparros; Falcon, Maria del Carmen Prieto; Batista, Vinicius Bianchi; Vazquez, Rosa Maria Lepe

    2015-01-01

    Penetrating atherosclerotic aortic ulcer is a rare entity with poor prognosis in the setting of acute aortic syndrome. In the literature, cases like the present one, located in the aortic arch, starting with chest pain and evolving with dysphonia, are even rarer. The present report emphasizes the role played by computed tomography in the diagnosis of penetrating atherosclerotic ulcer as well as in the differentiation of this condition from other acute aortic syndromes. Additionally, the authors describe a new therapeutic approach represented by a hybrid endovascular surgical procedure for treatment of the disease. (author)

  1. Hybrid treatment of penetrating aortic ulcer

    Energy Technology Data Exchange (ETDEWEB)

    Lara, Juan Antonio Herrero; Martins-Romeo, Daniela de Araujo; Escudero, Carlos Caparros; Falcon, Maria del Carmen Prieto; Batista, Vinicius Bianchi, E-mail: jaherrero5@hotmail.com [Unidade de Gestao Clinica (UGC) de Diagnostico por Imagem - Hosppital Universitario Virgen Macarena, Sevilha (Spain); Vazquez, Rosa Maria Lepe [Unit of Radiodiagnosis - Hospital Nuestra Senora de la Merced, Osuna, Sevilha (Spain)

    2015-05-15

    Penetrating atherosclerotic aortic ulcer is a rare entity with poor prognosis in the setting of acute aortic syndrome. In the literature, cases like the present one, located in the aortic arch, starting with chest pain and evolving with dysphonia, are even rarer. The present report emphasizes the role played by computed tomography in the diagnosis of penetrating atherosclerotic ulcer as well as in the differentiation of this condition from other acute aortic syndromes. Additionally, the authors describe a new therapeutic approach represented by a hybrid endovascular surgical procedure for treatment of the disease. (author)

  2. Surgery for acute Type I aortic dissection without resection of supra-aortic entry sites leads to unfavourable aortic remodelling.

    Science.gov (United States)

    Heo, Woon; Song, Suk-Won; Lee, Kwang-Hun; Lee, Shin-Young; Kim, Tae-Hoon; Baek, Min-Young; Yoo, Kyung-Jong

    2018-01-29

    This study aimed to evaluate the impact of remnant re-entries in arch branches on postoperative change in the aortic arch and descending aortic diameters and the rate of major adverse aortic events. Between January 2010 and December 2016, 249 patients underwent surgery for acute Type I aortic dissection. Patients who underwent total arch replacement, had Marfan syndrome or had intramural haematoma were excluded. Seventy-two patients with predischarge and follow-up computed tomography scans were enrolled. Patients with and without re-entries in the arch branches after surgery were assigned to the supra-aortic entry (SAE, n = 21) and no supra-aortic entry (n = 51) groups, respectively. Diameters were measured at 7 levels: the innominate artery, left common carotid artery, left subclavian artery, 20 mm distal to the left subclavian artery, pulmonary artery bifurcation, coeliac axis and maximal diameter of the descending thoracic aorta. Growth rates at the levels of the pulmonary artery bifurcation and 20 mm distal to the left subclavian artery were significantly higher in the SAE group than in the no supra-aortic entry group. The rate of freedom from major adverse aortic events (annual growth >5 mm or maximal diameter of the descending thoracic aorta >50 mm) at 5 years was significantly higher in the no supra-aortic entry group than in the SAE group. Remnant SAE leads to unfavourable aortic remodelling after acute Type I aortic dissection repair. © The Author(s) 2018. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

  3. Early results of valve-sparing ascending aortic replacement in type A aortic dissection and aortic insufficiency

    Directory of Open Access Journals (Sweden)

    М. Л. Гордеев

    2016-08-01

    Full Text Available Aim: The study was designed to investigate predictors of effective valve-sparing ascending aortic replacement in patients with Stanford type A aortic dissection combined with aortic insufficiency and to analyze efficacy and safety of this kind of surgery.Methods: From January 2010 to December 2015, 49 patients with Stanford type A aortic dissection combined with aortic insufficiency underwent ascending aortic replacement. All patients were divided into 3 groups: valve-sparing procedures (group 1, n = 11, combined aortic valve and supracoronary ascending aortic replacement (group 2, n = 12, and Bentall procedure (group 3, n = 26. We assessed the initial status of patients, incidence of complications and efficacy of valve-sparing ascending aortic replacement.Results: The hospital mortality rate was 8.2% (4/49 patients. The amount of surgical correction correlated with the initial diameter of the aorta at the level of the sinuses of Valsalva. During the hospital period, none of patients from group 1 developed aortic insufficiency exceeding Grade 2 and the vast majority of patients had trivial aortic regurgitation. The parameters of cardiopulmonary bypass, cross-clamp time and circulatory arrest time did not correlate with the initial size of the ascending aorta and aortic valve blood flow impairment, neither did they influence significantly the incidence and severity of neurological complications. The baseline size of the ascending aorta and degree of aortic regurgitation did not impact the course of the early hospital period.Conclusions: Supracoronary ascending aortic replacement combined with aortic valve repair in ascending aortic dissection and aortic regurgitation is effective and safe. The initial size of the ascending aorta and aortic arch do not influence immediate results. The diameter of the aorta at the level of the sinuses of Valsalva and the condition of aortic valve leaflets could be considered as the limiting factors. Further long

  4. [Metabolic syndrome and aortic stiffness].

    Science.gov (United States)

    Simková, A; Bulas, J; Murín, J; Kozlíková, K; Janiga, I

    2010-09-01

    The metabolic syndrome (MS) is a cluster of risk factors that move the patient into higher level of risk category of cardiovascular disease and the probability of type 2 diabetes mellitus manifestation. Definition of MS is s based on the presence of selected risk factors as: abdominal obesity (lager waist circumpherence), atherogenic dyslipidemia (low value of HDL-cholesterol and increased level of triglycerides), increased fasting blood glucose (or type 2 DM diagnosis), higher blood pressure or antihypertensive therapy. In 2009 there were created harmonizing criteria for MS definition; the condition for assignment of MS is the presence of any 3 criteria of 5 mentioned above. The underlying disorder of MS is an insulin resistance or prediabetes. The patients with MS more frequently have subclinical (preclinical) target organ disease (TOD) which is the early sings of atherosclerosis. Increased aortic stiffness is one of the preclinical diseases and is defined by pathologically increased carotidofemoral pulse wave velocity in aorta (PWV Ao). With the aim to assess the influence of MS on aortic stiffness we examined the group of women with arterial hypertension and MS and compare them with the group of women without MS. The aortic stiffness was examined by Arteriograph--Tensiomed, the equipment working on the oscillometric principle in detection of pulsations of brachial artery. This method determines the global aortic stiffness based on the analysis of the shape of pulse curve of brachial artery. From the cohort of 49 pts 31 had MS, the subgroups did not differ in age or blood pressure level. The mean number of risk factors per person in MS was 3.7 comparing with 1.7 in those without MS. In the MS group there was more frequently abdominal obesity present (87% vs 44%), increased fasting blood glucose (81% vs 22%) and low HDL-cholesterol level. The pulse wave velocity in aorta, PWV Ao, was significantly higher in patients with MS (mean value 10,19 m/s vs 8,96 m

  5. Aortic elongation in aortic aneurysm and dissection: the Tübingen Aortic Pathoanatomy (TAIPAN) project.

    Science.gov (United States)

    Krüger, Tobias; Sandoval Boburg, Rodrigo; Lescan, Mario; Oikonomou, Alexandre; Schneider, Wilke; Vöhringer, Luise; Lausberg, Henning; Bamberg, Fabian; Blumenstock, Gunnar; Schlensak, Christian

    2018-01-24

    To study the lengths and diameters of aortic segments in healthy and diseased aortas and to assess the role of aortic elongation in Type A aortic dissection (TAD) prediction. Ectasia and aneurysm were defined by ascending aorta diameters of 45-54 mm and ≥55 mm, respectively. Computed tomography angiography studies of 256 healthy, 102 ectasia, 38 aneurysm, 17 pre-TAD and 166 TAD aortas were analysed using curved multiplanar reformats. The study groups were structurally equal. The diameter of the ascending aorta was 35 mm in the control group and was larger (P TAD (43 mm) and TAD (56 mm) groups. The length of the ascending aorta from the aortic annulus to the brachiocephalic trunk was 92 mm in the control group, 113 mm in the ectasia group, 120 mm in the aneurysm group and 111 mm and 118 mm in the pre-TAD and TAD groups (all P TAD group and 48% of the TAD group. The correlation between the diameter and the length of the ascending aorta was r = 0.752; therefore, both parameters must be examined separately. A score considering both parameters identified 23.5% of pre-TAD patients, significantly more than the diameter alone, and 31.4% of ectasia aortas were elongated. Patients with ectatic (45-54 mm diameter) and elongated (≥120 mm) ascending aortas represent a high-risk subpopulation for TAD. © The Author(s) 2018. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

  6. Lagrangian coherent structures in the left ventricle in the presence of aortic valve regurgitation

    Science.gov (United States)

    di Labbio, Giuseppe; Vetel, Jerome; Kadem, Lyes

    2017-11-01

    Aortic valve regurgitation is a rather prevalent condition where the aortic valve improperly closes, allowing filling of the left ventricle of the heart to occur partly from backflow through the aortic valve. Although studies of intraventricular flow are rapidly gaining popularity in the fluid dynamics research community, much attention has been given to the left ventricular vortex and its potential for early detection of disease, particularly in the case of dilated cardiomyopathy. Notably, the subsequent flow in the left ventricle in the presence of aortic valve regurgitation ought to be appreciably disturbed and has yet to be described. Aortic valve regurgitation was simulated in vitro in a double-activation left heart duplicator and the ensuing flow was captured using two-dimensional time-resolved particle image velocimetry. Further insight into the regurgitant flow is obtained by computing attracting and repelling Lagrangian coherent structures. An interesting interplay between the two inflowing jets and their shear layer roll-up is observed for various grades of regurgitation. This study highlights flow features which may find use in further assessing regurgitation severity.

  7. Aging impairs smooth muscle-mediated regulation of aortic stiffness: a defect in shock absorption function?

    Science.gov (United States)

    Gao, Yuan Z.; Saphirstein, Robert J.; Yamin, Rina; Suki, Bela

    2014-01-01

    Increased aortic stiffness is an early and independent biomarker of cardiovascular disease. Here we tested the hypothesis that vascular smooth muscle cells (VSMCs) contribute significantly to aortic stiffness and investigated the mechanisms involved. The relative contributions of VSMCs, focal adhesions (FAs), and matrix to stiffness in mouse aorta preparations at optimal length and with confirmed VSMC viability were separated by the use of small-molecule inhibitors and activators. Using biomechanical methods designed for minimal perturbation of cellular function, we directly quantified changes with aging in aortic material stiffness. An alpha adrenoceptor agonist, in the presence of NG-nitro-l-arginine methyl ester (l-NAME) to remove interference of endothelial nitric oxide, increases stiffness by 90–200% from baseline in both young and old mice. Interestingly, increases are robustly suppressed by the Src kinase inhibitor PP2 in young but not old mice. Phosphotyrosine screening revealed, with aging, a biochemical signature of markedly impaired agonist-induced FA remodeling previously associated with Src signaling. Protein expression measurement confirmed a decrease in Src expression with aging. Thus we report here an additive model for the in vitro biomechanical components of the mouse aortic wall in which 1) VSMCs are a surprisingly large component of aortic stiffness at physiological lengths and 2) regulation of the VSMC component through FA signaling and hence plasticity is impaired with aging, diminishing the aorta's normal shock absorption function in response to stressors. PMID:25128168

  8. On the Laurent polynomial rings

    International Nuclear Information System (INIS)

    Stefanescu, D.

    1985-02-01

    We describe some properties of the Laurent polynomial rings in a finite number of indeterminates over a commutative unitary ring. We study some subrings of the Laurent polynomial rings. We finally obtain two cancellation properties. (author)

  9. Infected aortic aneurysm and inflammatory aortic aneurysm. In search of an optimal differential diagnosis

    International Nuclear Information System (INIS)

    Ishizaka, Nobukazu; Sohmiya, Koichi; Miyamura, Masatoshi; Umeda, Tatsuya; Tsuji, Motomu; Katsumata, Takahiro; Miyata, Tetsuro

    2012-01-01

    Infected aortic aneurysm and inflammatory aortic aneurysm each account for a minor fraction of the total incidence of aortic aneurysm and are associated with periaortic inflammation. Despite the similarity, infected aortic aneurysm generally shows a more rapid change in clinical condition, leading to a fatal outcome; in addition, delayed diagnosis and misuse of corticosteroid or immunosuppressing drugs may lead to uncontrolled growth of microorganisms. Therefore, it is mandatory that detection of aortic aneurysm is followed by accurate differential diagnosis. In general, infected aortic aneurysm appears usually as a saccular form aneurysm with nodularity, irregular configuration; however, the differential diagnosis may not be easy sometimes for the following reasons: symptoms, such as abdominal and/or back pain and fever, and blood test abnormalities, such as elevated C-reactive protein and enhanced erythrocyte sedimentation rate, are common in infected aortic aneurysm, but they are not found infrequently in inflammatory aortic aneurysm; some inflammatory aortic aneurysms are immunoglobulin (Ig) G4-related, but not all of them; the prevalence of IgG4 positivity in infected aortic aneurysm has not been well investigated; enhanced uptake of 18F-fluorodeoxyglucose (FDG) by 18F-FDG-positron emission tomography may not distinguish between inflammation mediated by autoimmunity and that mediated by microorganism infection. Here we discuss the characteristics of these two forms of aortic aneurysm and the points of which we have to be aware before reaching a final diagnosis. (author)

  10. Delayed Presentation of a Giant Ascending Aortic Aneurysm following Aortic Valve Replacement

    Directory of Open Access Journals (Sweden)

    Tugrul Göncü

    2009-01-01

    Full Text Available Giant ascending aortic aneurysm formation following aortic valve replacement is rare. A 28-year-old man who underwent aortic valve replacement with a prosthetic valve for aortic regurgitation secondary to congenital bicuspid aortic valve about 10 years ago was diagnosed with a giant ascending aortic aneurysm about 16 cm in diameter in follow-up. The aneurysm was resected leaving the functional old mechanical prosthesis in place and implanted a 34-mm Hemashield woven graft, associated with the left and right coronary artery button implantation. Histological findings of the aortic aneurysm wall showed cystic medial necrosis. The postoperative course was uneventful and postoperative examination demonstrated good surgical results.

  11. Heavy ion storage rings

    International Nuclear Information System (INIS)

    Schuch, R.

    1987-01-01

    A brief overview of synchrotron storage rings for heavy ions, which are presently under construction in different accelerator laboratories is given. Ions ranging from protons up to uranium ions at MeV/nucleon energies will be injected into these rings using multiturn injection from the accelerators available or being built in these laboratories. After injection, it is planned to cool the phase space distribution of the ions by merging them with cold electron beams or laser beams, or by using stochastic cooling. Some atomic physics experiments planned for these rings are presented. 35 refs

  12. Faithfully quadratic rings

    CERN Document Server

    Dickmann, M

    2015-01-01

    In this monograph the authors extend the classical algebraic theory of quadratic forms over fields to diagonal quadratic forms with invertible entries over broad classes of commutative, unitary rings where -1 is not a sum of squares and 2 is invertible. They accomplish this by: (1) Extending the classical notion of matrix isometry of forms to a suitable notion of T-isometry, where T is a preorder of the given ring, A, or T = A^2. (2) Introducing in this context three axioms expressing simple properties of (value) representation of elements of the ring by quadratic forms, well-known to hold in

  13. Transcatheter Aortic Valve Replacement in Europe

    DEFF Research Database (Denmark)

    Mylotte, Darren; Osnabrugge, Ruben L J; Windecker, Stephan

    2013-01-01

    The authors sought to examine the adoption of transcatheter aortic valve replacement (TAVR) in Western Europe and investigate factors that may influence the heterogeneous use of this therapy.......The authors sought to examine the adoption of transcatheter aortic valve replacement (TAVR) in Western Europe and investigate factors that may influence the heterogeneous use of this therapy....

  14. Graft infections after surgical aortic reconstructions

    NARCIS (Netherlands)

    Berger, P.

    2015-01-01

    Prosthetic vascular grafts are frequently used to reconstruct (part) of the aorta. Every surgical procedure caries a certain risk for infection and when a prosthetic aortic graft is implanted, this may lead to an aortic graft infection (AGI). Endovascular techniques have gradually replaced open

  15. Severe aortic stenosis: diagnosis, treatment and prognosis

    NARCIS (Netherlands)

    M.W.A. van Geldorp (Martijn)

    2013-01-01

    textabstractDegenerative aortic stenosis is the most common valvular heart disease in developed countries. The prevalence of severe aortic stenosis increases with age from 1% in people below 65 years of age to nearly 6% in people over the age of 85. Since the population life expectancy continues to

  16. Valve-sparing aortic root replacement†

    NARCIS (Netherlands)

    Koolbergen, David R.; Manshanden, Johan S. J.; Bouma, Berto J.; Blom, Nico A.; Mulder, Barbara J. M.; de Mol, Bas A. J. M.; Hazekamp, Mark G.

    2015-01-01

    To evaluate our results of valve-sparing aortic root replacement and associated (multiple) valve repair. From September 2003 to September 2013, 97 patients had valve-sparing aortic root replacement procedures. Patient records and preoperative, postoperative and recent echocardiograms were reviewed.

  17. MRI evaluation of the aortic disease

    International Nuclear Information System (INIS)

    Kapuscinski, O.; Polkowski, J.; Zaleska, T.; Walecki, J.; Biesiadko, M.

    1994-01-01

    The goal of our study was to establish the value of MRI in diagnosing aortic disease. During 3 years period 46 patients were examined (12 women aged from 6 to 62 years and 34 men aged from 8 to 72 years). In 28 cases the thoracic aorta was examined, in 6 cases the abdominal aorta and in 12 - both the thoracic and the abdominal aorta. MR images were performed on MRT 50 A Toshiba unit 0.5 T. MR images demonstrated aortic aneurysm (caused by atherosclerosis or trauma), aortic dissections, aortic anomalies (i.e. in Turner syndrome) and non-specific aortitis and vasculitis. We regard MRI as preferable noninvasive imaging technique in diagnosing aortic disease. (author)

  18. On arbitrarily graded rings

    Indian Academy of Sciences (India)

    58

    paper is devoted to the study of arbitrary rings graded through arbitrary sets. .... which recover certain multiplicative relations among the homogeneous components ... instance the case in which the grading set A is an Abelian group, where the ...

  19. The g-2 ring

    CERN Multimedia

    1974-01-01

    The precise measurement of "g-2", the anomalous magnetic moment of the muon, required a special muon storage ring with electrostatic focussing and very accurate knowledge of the magnetic bending field. For more details see under photo 7405430.

  20. [Liesegang's rings resembling helminthiasis].

    Science.gov (United States)

    Zámecník, M; Riedl, I

    1996-12-01

    So called Liesegang's rings are lamellar corpuscles which develop after periodical precipitation of oversaturated solutions in gel medium. They can occur in cysts, closed cavities, inflammatory exudates and necroses. They resemble parasitic eggs, larvae or adult forms. A case of 28-year-old woman is presented with many Liesegang's rings in a stuff from dilated renal calyx. Their preliminary evaluation considered helminths, especially Dioctophyma renale.

  1. Storage ring group summary

    International Nuclear Information System (INIS)

    King, N.M.

    1980-01-01

    The Storage Ring Group set out to identify and pursue salient problems in accelerator physics for heavy ion fusion, divorced from any particular reference design concept. However, it became apparent that some basic parameter framework was required to correlate the different study topics. As the Workshop progressed, ring parameters were modified and updated. Consequently, the accompanying papers on individual topics will be found to refer to slightly varied parameters, according to the stage at which the different problems were tackled

  2. The rings of Uranus

    Science.gov (United States)

    Elliot, J. L.; Dunham, E.; Mink, D.

    1977-01-01

    A description is given of the observation of five brief occultations of the star SAO 158687 which occurred both before and after its occultation by Uranus on March 10, 1977. The events were observed with a three-channel occultation photometer, attached to a 91-cm telescope. The observations indicate that at least five rings encircle the planet Uranus. Possible reasons for the narrowness of the Uranus rings are discussed.

  3. Treatment strategy for ruptured abdominal aortic aneurysms.

    Science.gov (United States)

    Davidovic, L

    2014-07-01

    Rupture is the most serious and lethal complication of the abdominal aortic aneurysm. Despite all improvements during the past 50 years, ruptured abdominal aortic aneurysms are still associated with very high mortality. Namely, including patients who die before reaching the hospital, the mortality rate due to abdominal aortic aneurysm rupture is 90%. On the other hand, during the last twenty years, the number of abdominal aortic aneurysms significantly increased. One of the reasons is the fact that in majority of countries the general population is older nowadays. Due to this, the number of degenerative AAA is increasing. This is also the case for patients with abdominal aortic aneurysm rupture. Age must not be the reason of a treatment refusal. Optimal therapeutic option ought to be found. The following article is based on literature analysis including current guidelines but also on my Clinics significant experience. Furthermore, this article show cases options for vascular medicine in undeveloped countries that can not apply endovascular procedures at a sufficient level and to a sufficient extent. At this moment the following is evident. Thirty-day-mortality after repair of ruptured abdominal aortic aneurysms is significantly lower in high-volume hospitals. Due to different reasons all ruptured abdominal aortic aneurysms are not suitable for EVAR. Open repair of ruptured abdominal aortic aneurysm should be performed by experienced open vascular surgeons. This could also be said for the treatment of endovascular complications that require open surgical conversion. There is no ideal procedure for the treatment of AAA. Each has its own advantages and disadvantages, its own limits and complications, as well as indications and contraindications. Future reductions in mortality of ruptured abdominal aortic aneurysms will depend on implementation of population-based screening; on strategies to prevent postoperative organ injury and also on new medical technology

  4. [Modern aortic surgery in Marfan syndrome--2011].

    Science.gov (United States)

    Kallenbach, K; Schwill, S; Karck, M

    2011-09-01

    Marfan syndrome is a hereditary disease with a prevalence of 2-3 in 10,000 births, leading to a fibrillin connective tissue disorder with manifestations in the skeleton, eye, skin, dura mater and in particular the cardiovascular system. Since other syndromes demonstrate similar vascular manifestations, but therapy may differ significantly, diagnosis should be established using the revised Ghent nosology in combination with genotypic analysis in specialized Marfan centres. The formation of aortic root aneurysms with the subsequent risk of acute aortic dissection type A (AADA) or aortic rupture limits life expectancy in patients with Marfan syndrome. Therefore, prophylactic replacement of the aortic root needs to be performed before the catastrophic event of AADA can occur. The goal of surgery is the complete resection of pathological aortic tissue. This can be achieved with excellent results by using a (mechanically) valved conduit that replaces both the aortic valve and the aortic root (Bentall operation). However, the need for lifelong anticoagulation with Coumadin can be avoided using the aortic valve sparing reimplantation technique according to David. The long-term durability of the reconstructed valve is favourable, and further technical improvements may improve longevity. Although results of prospective randomised long-term studies comparing surgical techniques are lacking, the David operation has become the surgical method of choice for aortic root aneurysms, not only at the Heidelberg Marfan Centre. Replacement of the aneurysmal dilated aortic arch is performed under moderate hypothermic circulatory arrest combined with antegrade cerebral perfusion using a heart-lung machine, which we also use in thoracic or thoracoabdominal aneurysms. Close post-operative follow-up in a Marfan centre is pivotal for the early detection of pathological changes on the diseased aorta.

  5. MR imaging of aortic coarctation

    International Nuclear Information System (INIS)

    Beslic, S.

    2004-01-01

    Purpose. The purpose of this paper is to analyse the contribution of MRI as diagnostic procedure in the preoperative diagnosis of aortic coarctation (CoA), in patients with clinical and echocardiographic suspicion for this disease. Patients and methods. During the period of three years, eight patients were examined, 5 (62.5%) male and 3 (37.5%) female patients with clinical echocardiographic suspicion of CoA. The ratio between male and female patients was 1.7 : 1. The youngest patient was 3 and the oldest 46 years (median age was 15 years). Without administration of contrast media and using body coil the examinations were performed with MR machine Magnetom 1.0 Tesla ( S iemens ) , with the slice thickness of 6 mm, Fast spin-echo (FSE) T1W sequences, Cine gradient echo (GRE) sequence with slab 7 mm and time of flight (TOF) sequence with MIP reconstructions were applied. During the examinations the patients underwent also ECG gating. Examinations were done in axial, coronal and oblique sagittal projections with measuring of the dimensions of cardiovascular structures. Results. CoA was found in 8 (100%) patients. In 7 (87.5%) cases, coarctation developed at isthmus and in one case, coarctation was detected at the horizontal part of aortic arch, between the truncus arteriosus of the left carotid communis artery. Aortal insufficiency was found in 7 (87.5%) patients; in four of them (50%), bicuspidia was confirmed (bicuspid aortic valve), 7 (87.5%) patients had slightly expressed hypertrophy of the left ventricle. Two (25%) patients had dilatation of the ascendant aorta, six (75%) wider outgoing vessels of the aortic arch, four (50%) had well developed arterial collaterals and 2 (25%) patients rib notching. In 2 (25%) patients as side finding thymus persistent was found. Average diameter of coarctation was 10 mm. In one patient, CoA was accompanied with stenosis of pulmonary artery, in one with ventricular septal defect, and one with tricuspid insufficiency. The results

  6. Imaging techniques in aortic valve and root surgery

    NARCIS (Netherlands)

    Regeer, M.V.

    2017-01-01

    Aortic valve sparing surgery for aortic regurgitation and/or aortopathy serves as an alternative to aortic valve and root replacement. One of the advantages of aortic valve sparing surgery over conventional replacement is that there is no need for life-long anticoagulation, which is particularly

  7. The use of transcatheter aortic valve replacement vs surgical aortic valve replacement for the treatment of aortic stenosis

    Directory of Open Access Journals (Sweden)

    Jensen HA

    2015-08-01

    Full Text Available Hanna A Jensen, Lillian L Tsai, Vinod H Thourani Division of Cardiothoracic Surgery, Joseph B Whitehead Department of Surgery, Structural Heart and Valve Center, Emory University School of Medicine, Atlanta, GA, USA Abstract: Severe aortic stenosis (AS is associated with considerable morbidity and mortality and is increasing in prevalence as the global population increases. Since AS primarily affects the elderly, many of these patients have comorbidities that make them poor candidates for the gold standard treatment for AS, surgical aortic valve replacement. Transcatheter aortic valve replacement has emerged as a novel technology for the management of AS in higher risk patients over the past decade. Randomized trials have established the safety and efficacy of transcatheter aortic valve replacement, and the medical community has rallied to identify the patients who are most suitable for this transformative treatment. This review focuses on outlining the key procedural differences, describing the unique challenges of both operations, and finally assessing and comparing outcomes both on a general level and in challenging patient subgroups. Keywords: aortic valve replacement, transcatheter aortic valve replacement, surgical aortic valve replacement 

  8. Aortic root surgery in Marfan syndrome: Comparison of aortic valve-sparing reimplantation versus composite grafting.

    Science.gov (United States)

    Karck, Matthias; Kallenbach, Klaus; Hagl, Christian; Rhein, Christine; Leyh, Rainer; Haverich, Axel

    2004-02-01

    The objective of this study was to compare the results of aortic valve-sparing reimplantation and aortic root replacement with mechanical valve conduits in patients with Marfan syndrome undergoing operation for aortic root aneurysms. Patients and methods Between March 1979 and April 2002, 119 patients with clinical evidence of Marfan syndrome underwent composite graft replacement with mechanical valve conduits (n = 74) or aortic valve-sparing reimplantation according to David (n = 45). The underlying causes were aortic dissection type A (43 patients) and aneurysms (76 patients). Patients undergoing aortic valve reimplantation were younger compared with patients undergoing composite grafting (28 vs 35 years, P =.002) and had longer intraoperative aortic crossclamp times (125 vs 78 minutes, P valve reimplantation (P =.15). Mean follow-up was 30 months for patients undergoing aortic valve reimplantation and 114 months for patients undergoing composite grafting. Freedom from reoperation and death after 5 years postoperatively was 92% and 89% in patients undergoing composite grafting and 84% and 96% in patients undergoing aortic valve reimplantation (P =.31; P =.54), respectively. Thromboembolic complications or late postoperative bleeding occurred in 17 patients undergoing composite grafting, and an early postoperative event occurred in 1 patient undergoing aortic valve reimplantation. The results of aortic valve reimplantation and composite grafting of the aortic valve and ascending aorta with mechanical valve conduits are similar with regard to early and mid-term postoperative mortality and to the incidence of late reoperations in patients with Marfan syndrome. The low risk of thromboembolic or bleeding complications favors aortic valve reimplantation in these patients.

  9. Vascular rings in Bucaramanga 1999-2002: clinical Series and revision of the literature

    International Nuclear Information System (INIS)

    L M, Sosa Avila; J, Niederbacher; O, Fernandez; A, Duran

    2003-01-01

    They are denominated vascular rings to the group of early anomalies of the embryologic development of the aortic arches that they cause a spectrum of clinical manifestations for the compression of the air way and of the digestive tract. The authors report 8 cases presented among 1999-2002, with an average of age of 10 months at the moment of the diagnosis, 6 arches aortic right and two with double aortic arch. The strider from the birth and the syndrome appearance bronchia-obstructive during the first month was presented in all the cases and the digestive manifestations as dysphagia they accompanied to the cases of double aortic arch. The thorax x-ray allowed valuing the aortic arch it forms the shepherd's aortic crook and of the right the artery right subclavian in 62.5%, and the echography in 100% of the cases; the x-ray of digestive roads evidenced fixed notch in 71% of the cases. The echocardiogram allowed evaluating the origin of the glasses anomalous of the shepherd's crook in 62.5%. It was carried out surgical treatment in 87,5% of the cases, with complications pos-surgical in 1/7 consistent in chylethorax, and subcutaneous emphysema. The authors recommend evaluating for vascular ring to everything recently born with strider and rough obstruction by means of thorax x-ray, x-ray of digestive roads and echocardiogram. In selected cases it would be practiced endoscopy of the air way and the aortogram or the magnetic resonance of the thorax and their vessel for confirmation of the definitive diagnosis

  10. Elastin-derived peptides promote abdominal aortic aneurysm formation by modulating M1/M2 macrophage polarization1

    Science.gov (United States)

    Dale, Matthew A; Xiong, Wanfen; Carson, Jeffrey S; Suh, Melissa K; Karpisek, Andrew D.; Meisinger, Trevor M.; Casale, George P.; Baxter, B. Timothy

    2016-01-01

    Abdominal aortic aneurysm (AAA) is a dynamic vascular disease characterized by inflammatory cell invasion and extracellular matrix (ECM) degradation. Damage to elastin in the ECM results in release of elastin-derived peptides (EDPs), which are chemotactic for inflammatory cells such as monocytes. Their effect on macrophage polarization is less well known. Pro-inflammatory M1 macrophages initially are recruited to sites of injury but, if their effects are prolonged, they can lead to chronic inflammation that prevents normal tissue repair. Conversely, anti-inflammatory M2 macrophages reduce inflammation and aid in wound healing. Thus, a proper M1/M2 ratio is vital for tissue homeostasis. AAA tissue reveals a high M1/M2 ratio where pro-inflammatory cells and their associated markers dominate. In the present study, in vitro treatment of bone marrow-derived macrophages with EDPs induced M1 macrophage polarization. By using C57Bl/6 mice, antibody-mediated neutralization of EDPs reduced aortic dilation, matrix metalloproteinase activity, and pro-inflammatory cytokine expression at early and late time points after aneurysm induction. Furthermore, direct manipulation of the M1/M2 balance altered aortic dilation. Injection of M2 polarized macrophages reduced aortic dilation after aneurysm induction. EDPs promoted a pro-inflammatory environment in aortic tissue by inducing M1 polarization and neutralization of EDPs attenuated aortic dilation. The M1/M2 imbalance is vital to aneurysm formation. PMID:27183603

  11. Some Aspects of Ring Theory

    CERN Document Server

    Herstein, IN

    2011-01-01

    S. Amitsur: Associative rings with identities.- I.N. Herstein: Topics in ring theory.- N. Jacobson: Representation theory of Jordan algebras.- I. Kaplansky: The theory of homological dimension.- D. Buchsbaum: Complexes in local ring theory.- P.H. Cohn: Two topics in ring theory.- A.W. Goldie: Non-commutative localisation.

  12. Factors Affecting Optimal Aortic Remodeling After Thoracic Endovascular Aortic Repair of Type B (IIIb) Aortic Dissection

    International Nuclear Information System (INIS)

    Chen, I-Ming; Chen, Po-Lin; Huang, Chun-Yang; Weng, Shih-Hsien; Chen, Wei-Yuan; Shih, Chun-Che

    2017-01-01

    PurposeThe purpose of this study was to determine factors associated with entire aortic remodeling after thoracic endovascular aortic repair (TEVAR) in patients with type B dissection.Materials and MethodsThe patients with type B (IIIb) dissections who underwent TEVAR from 2006 to 2013 with minimum of 2 years of follow-up computed tomography data were retrospectively reviewed. Based on the status of false lumen remodeling of entire aorta, patients were divided into three groups: complete regression, total thrombosis, and inadequate regression with patent abdominal false lumen.ResultsA total of 90 patients (72 males, 18 females; mean age 56.6 ± 16.4 years) were included and divided into the complete regression (n = 22), total thrombosis (n = 18), and inadequate regression (n = 50) groups. Multivariate logistic regression analysis indicated that dissection extension to iliac arteries, increased preoperative number of dissection tear over abdominal aorta, and decreased preoperative abdominal aorta bifurcation true lumen ratio, as compared between the inadequate and complete regression groups, were associated with a persistent false lumen (odds ratio = 33.33, 2.304, and 0.021; all, p ≤ 0.012). Comparison of 6, 12, and 24 months postoperative data revealed no significant differences at any level, suggesting that the true lumen area ratio might not change after 6 months postoperatively.ConclusionsIncreased preoperative numbers of dissection tear around the abdominal visceral branches, dissection extension to the iliac arteries, and decreased preoperative true lumen area ratio of abdominal aorta are predictive of entire aortic remodeling after TEVAR in patients with type B dissection.Level of EvidenceIII.

  13. Factors Affecting Optimal Aortic Remodeling After Thoracic Endovascular Aortic Repair of Type B (IIIb) Aortic Dissection

    Energy Technology Data Exchange (ETDEWEB)

    Chen, I-Ming [National Yang Ming University, Institute of Clinical Medicine, School of Medicine (China); Chen, Po-Lin; Huang, Chun-Yang [National Yang Ming University, Department of Medicine, School of Medicine (China); Weng, Shih-Hsien; Chen, Wei-Yuan; Shih, Chun-Che, E-mail: ccshih@vghtpe.gov.tw [National Yang Ming University, Institute of Clinical Medicine, School of Medicine (China)

    2017-05-15

    PurposeThe purpose of this study was to determine factors associated with entire aortic remodeling after thoracic endovascular aortic repair (TEVAR) in patients with type B dissection.Materials and MethodsThe patients with type B (IIIb) dissections who underwent TEVAR from 2006 to 2013 with minimum of 2 years of follow-up computed tomography data were retrospectively reviewed. Based on the status of false lumen remodeling of entire aorta, patients were divided into three groups: complete regression, total thrombosis, and inadequate regression with patent abdominal false lumen.ResultsA total of 90 patients (72 males, 18 females; mean age 56.6 ± 16.4 years) were included and divided into the complete regression (n = 22), total thrombosis (n = 18), and inadequate regression (n = 50) groups. Multivariate logistic regression analysis indicated that dissection extension to iliac arteries, increased preoperative number of dissection tear over abdominal aorta, and decreased preoperative abdominal aorta bifurcation true lumen ratio, as compared between the inadequate and complete regression groups, were associated with a persistent false lumen (odds ratio = 33.33, 2.304, and 0.021; all, p ≤ 0.012). Comparison of 6, 12, and 24 months postoperative data revealed no significant differences at any level, suggesting that the true lumen area ratio might not change after 6 months postoperatively.ConclusionsIncreased preoperative numbers of dissection tear around the abdominal visceral branches, dissection extension to the iliac arteries, and decreased preoperative true lumen area ratio of abdominal aorta are predictive of entire aortic remodeling after TEVAR in patients with type B dissection.Level of EvidenceIII.

  14. Aortography following subdiaphragmal aortic biopsy

    International Nuclear Information System (INIS)

    Schimmler, J.

    1982-01-01

    A juxtaposition of the subdiaphragmal and infrarenal translumbar aortic biopsy sites showed decisive advantages in favour of the higher site: a more stable position because of better anatomic fixation and rarer incidence of vascular alterations, a wider vascular lumen. Disadvantages lie in the fact that the large visceral arteries (especially Tr. coeliacus) branch off nearly and in the close anatomic relationship to large abdominal organs and the thoracal region. Evaluation of the radiographical image of the vascular tree after subdiaphragmal aortic biopsy showed an average 82% of the vessels to the area of the Knees to be assessable (renal arteries approximately 93%, popliteal arteries approximately 70%). Beyong, the method proved unsatisfactory: 52% of the vessels could not, or not safety, be evaluated. A relatively broad spectrum of indications by comparison with transfemoral catheter aortography had no influence on the rate of complications with reference to either method. A comparison of the topographic conditions shows the need for even more scrupulons observation of the technique in subdiaphragmal biopsy than in the infrarenal one. To sum up the results obtained, subdiaphregmal translumbar aortography is to be preferred to the infrarenal one where transfemoral catheter aortography is contra-indicated, within the limits mentioned. (orig.) [de

  15. Imaging of thoracic aortic dissection

    International Nuclear Information System (INIS)

    Vu, F.H.; Young, N.; Soo, Y.S.

    1994-01-01

    Acute thoracic aortic dissection has a high mortality rate if untreated, so the diagnosis must be rapidly made. Multiple imaging techniques are often used. This retrospective study from 1988 to 1993 assesses the usefulness in diagnosis of chest X-rays, computed tomography (CT) scanning, aortography, magnetic resonance imaging (MRI), trans-thoracic (TTE) and trans-oesophageal (TOE) echocardiography. Forty-two patients with a final clinical diagnosis of dissection were studied. The diagnosis was confirmed in 16 (13 at surgery and three at autopsy). Three died with dissection given as the only cause of death. Chest X-ray abnormalities were seen in all 19 patients with surgery or death from dissection, with a widened mediastinum and/or dilated aorta being present in 17. In the group of 16 patients with surgery or autopsy proof, CT scans found dissections in 9 out of 12 patients studied and correctly classified the type in only five. Aortography was preformed in five, with accurate depiction of dissection and type in all. TTE found dissections in three of eight patients imaged by this method. MRI and TOE were preformed each on two patients, with accurate depiction of dissection and type in each. Because of the relatively low sensitivity of CT scanning in defining aortic dissections Westmead Hospital is currently assessing the use of TOE as the prime imaging modality prior to surgical intervention. 17 refs., 4 tabs., 4 figs

  16. Ring correlations in random networks.

    Science.gov (United States)

    Sadjadi, Mahdi; Thorpe, M F

    2016-12-01

    We examine the correlations between rings in random network glasses in two dimensions as a function of their separation. Initially, we use the topological separation (measured by the number of intervening rings), but this leads to pseudo-long-range correlations due to a lack of topological charge neutrality in the shells surrounding a central ring. This effect is associated with the noncircular nature of the shells. It is, therefore, necessary to use the geometrical distance between ring centers. Hence we find a generalization of the Aboav-Weaire law out to larger distances, with the correlations between rings decaying away when two rings are more than about three rings apart.

  17. Ascending aortic injuries following blunt trauma.

    Science.gov (United States)

    Sun, Xiumei; Hong, Jenny; Lowery, Robert; Goldstein, Steven; Wang, Zuyue; Lindsay, Joseph; Hill, Peter C; Corso, Paul J

    2013-11-01

    The diagnosis and the management of traumatic thoracic aortic injuries have undergone significant changes due to new technology and improved prehospital care. Most of the discussions have focused on descending aortic injuries. In this review, we discuss the recent management of ascending aortic injuries. We found 5 cohort studies on traumatic aortic injuries and 11 case reports describing ascending aortic injuries between 1998 to the present through Medline research. Among case reports, 78.9% of cases were caused by motor vehicle accidents (MVA). 42.1% of patients underwent emergent open repair and the operative mortality was 12.5%. 36.8% underwent delayed repair. Associated injuries occurred in 84.2% of patients. Aortic valve injury was concurrent in 26.3% of patients. The incidence of ascending aortic injury ranged 1.9-20% in cohort studies. Traumatic injuries to the ascending aorta are relatively uncommon among survivors following blunt trauma. Aortography has been replaced by computed tomography and echocardiography as a diagnostic tool. Open repair, either emergent or delayed, remains the treatment of choice. © 2013 Wiley Periodicals, Inc.

  18. Aortic stenosis and vascular calcifications in alkaptonuria.

    Science.gov (United States)

    Hannoush, Hwaida; Introne, Wendy J; Chen, Marcus Y; Lee, Sook-Jin; O'Brien, Kevin; Suwannarat, Pim; Kayser, Michael A; Gahl, William A; Sachdev, Vandana

    2012-02-01

    Alkaptonuria is a rare metabolic disorder of tyrosine catabolism in which homogentisic acid (HGA) accumulates and is deposited throughout the spine, large joints, cardiovascular system, and various tissues throughout the body. In the cardiovascular system, pigment deposition has been described in the heart valves, endocardium, pericardium, aortic intima and coronary arteries. The prevalence of cardiovascular disease in patients with alkaptonuria varies in previous reports. We present a series of 76 consecutive adult patients with alkaptonuria who underwent transthoracic echocardiography between 2000 and 2009. A subgroup of 40 patients enrolled in a treatment study underwent non-contrast CT scans and these were assessed for vascular calcifications. Six of the 76 patients had aortic valve replacement. In the remaining 70 patients, 12 patients had aortic sclerosis and 7 patients had aortic stenosis. Unlike degenerative aortic valve disease, we found no correlation with standard cardiac risk factors. There was a modest association between the severity of aortic valve disease and joint involvement, however, we saw no correlation with urine HGA levels. Vascular calcifications were seen in the coronaries, cardiac valves, aortic root, descending aorta and iliac arteries. These findings suggest an important role for echocardiographic screening of alkaptonuria patients to detect valvular heart disease and cardiac CT to detect coronary artery calcifications. Published by Elsevier Inc.

  19. Aortic reconstruction with bovine pericardial grafts

    Directory of Open Access Journals (Sweden)

    Silveira Lindemberg Mota

    2003-01-01

    Full Text Available INTRODUCTION: Glutaraldehyde-treated crimped bovine pericardial grafts are currently used in aortic graft surgery. These conduits have become good options for these operations, available in different sizes and shapes and at a low cost. OBJECTIVE:To evaluate the results obtained with bovine pericardial grafts for aortic reconstruction, specially concerning late complications. METHOD: Between January 1995 and January 2002, 57 patients underwent different types of aortic reconstruction operations using bovine pericardial grafts. A total of 29 (50.8% were operated on an urgent basis (mostly acute Stanford A dissection and 28 electively. Thoracotomy was performed in three patients for descending aortic replacement (two patients and aortoplasty with a patch in one. All remaining 54 underwent sternotomy, cardiopulmonary bypass and aortic resection. Deep hypothermia and total circulatory arrest was used in acute dissections and arch operations. RESULTS: Hospital mortality was 17.5%. Follow-up was 24.09 months (18.5 to 29.8 months confidence interval and complication-free actuarial survival curve was 92.3% (standard deviation ± 10.6. Two patients lately developed thoracoabdominal aneurysms following previous DeBakey II dissection and one died from endocarditis. One "patch" aortoplasty patient developed local descending aortic pseudoaneurysm 42 months after surgery. All other patients are asymptomatic and currently clinically evaluated with echocardiography and CT scans, showing no complications. CONCLUSION: Use of bovine pericardial grafts in aortic reconstruction surgery is adequate and safe, with few complications related to the conduits.

  20. Mapping Ring Particle Cooling across Saturn's Rings with Cassini CIRS

    Science.gov (United States)

    Brooks, Shawn M.; Spilker, L. J.; Edgington, S. G.; Pilorz, S. H.; Deau, E.

    2010-10-01

    Previous studies have shown that the rings' thermal inertia, a measure of their response to changes in the thermal environment, varies from ring to ring. Thermal inertia can provide insight into the physical structure of Saturn's ring particles and their regoliths. Low thermal inertia and quick temperature responses are suggestive of ring particles that have more porous or fluffy regoliths or that are riddled with cracks. Solid, coherent particles can be expected to have higher thermal inertias (Ferrari et al. 2005). Cassini's Composite Infrared Spectrometer has recorded millions of spectra of Saturn's rings since its arrival at Saturn in 2004 (personal communication, M. Segura). CIRS records far infrared radiation between 10 and 600 cm-1 (16.7 and 1000 µm) at focal plane 1 (FP1), which has a field of view of 3.9 mrad. Thermal emission from Saturn's rings peaks in this wavelength range. FP1 spectra can be used to infer ring temperatures. By tracking how ring temperatures vary, we can determine the thermal inertia of the rings. In this work we focus on CIRS observations of the shadowed portion of Saturn's rings. The thermal budget of the rings is dominated by the solar radiation absorbed by its constituent particles. When ring particles enter Saturn's shadow this source of energy is abruptly cut off. As a result, ring particles cool as they traverse Saturn's shadow. From these shadow observations we can create cooling curves at specific locations across the rings. We will show that the rings' cooling curves and thus their thermal inertia vary not only from ring to ring, but by location within the individual rings. This research was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under contract with NASA. Copyright 2010 California Institute of Technology. Government sponsorship acknowledged.

  1. Abscisic acid ameliorates atherosclerosis by suppressing macrophage and CD4+ T cell recruitment into the aortic wall.

    Science.gov (United States)

    Guri, Amir J; Misyak, Sarah A; Hontecillas, Raquel; Hasty, Alyssa; Liu, Dongmin; Si, Hongwei; Bassaganya-Riera, Josep

    2010-12-01

    Abscisic acid (ABA) is a natural phytohormone which improves insulin sensitivity and reduces adipose tissue inflammation when supplemented into diets of obese mice. The objective of this study was to investigate the mechanisms by which ABA prevents or ameliorates atherosclerosis. apolipoprotein E-deficient (ApoE(-/-)) mice were fed high-fat diets with or without ABA for 84 days. Systolic blood pressure was assessed on Days 0, 28, 56 and 72. Gene expression, immune cell infiltration and histological lesions were evaluated in the aortic root wall. Human aortic endothelial cells were used to examine the effect of ABA on 3',5'-cyclic adenosine monophosphate (cAMP) and nitric oxide (NO) production in vitro. We report that ABA-treated mice had significantly improved systolic blood pressure and decreased accumulation of F4/80(+)CD11b(+) macrophages and CD4(+) T cells in aortic root walls. At the molecular level, ABA significantly enhanced aortic endothelial nitric oxide synthase (eNOS) and tended to suppress aortic vascular cell adhesion molecule-1 (VCAM-1) and monocyte chemoattractant protein-1 (MCP-1) expression and plasma MCP-1 concentrations. ABA also caused a dose-dependent increase in intracellular concentrations of cAMP and NO and up-regulated eNOS mRNA expression in human aortic endothelial cells. This is the first report showing that ABA prevents or ameliorates atherosclerosis-induced hypertension, immune cell recruitment into the aortic root wall and up-regulates aortic eNOS expression in ApoE(-/-) mice. Copyright © 2010 Elsevier Inc. All rights reserved.

  2. The Rings of Saturn

    Science.gov (United States)

    Cuzzi, J. N.; Filacchione, G.; Marouf, E. A.

    2018-03-01

    One could become an expert on Saturn's iconic rings pretty easily in the early 1970s, as very little was known about them beyond the distinction between the A, B, and C rings, and the Cassini Division or "gap" between rings A and B (Alexander, 1962; Bobrov, 1970). Water ice was discovered spectroscopically on the ring particle surfaces, and radar and microwave emission observations proved that the particles must be centimeters to meters in size, consisting primarily, not just superficially, of water ice (Pollack, 1975). While a 2:1 orbital resonance with Mimas had long been suspected of having something to do with the Cassini Division, computers of the time were unable to model the subtle dynamical effects that we now know to dominate ring structure. This innocent state of affairs was exploded by the Voyager 1 and 2 encounters in 1980 and 1981. Spectacular images revealed filigree structure and odd regional color variations, and exquisitely detailed radial profiles of fluctuating particle abundance were obtained from the first stellar and radio occultations, having resolution almost at the scale of single particles. Voyager-era understanding was reviewed by Cuzzi et al. (1984) and Esposito et al. (1984). While the Voyager data kept ring scientists busy for decades, planning which led to the monumentally successful NASA-ESA-ASI Cassini mission, which arrived in 2004, had been under way even before Voyager got to Saturn. A review of pre-Cassini knowledge of Saturn's Rings can be found in Orton et al. (2009). This chapter will build on recent topical and process-specific reviews that treat the gamut of ring phenomena and its underlying physics in considerable detail (Colwell et al., 2009; Cuzzi et al., 2009; Horányi et al., 2009; Schmidt et al., 2009; Esposito, 2010; Tiscareno, 2013b; Esposito, 2014). We will follow and extend the general organization of Cuzzi et al. (2010), the most recent general discussion of Saturn's rings. For brevity and the benefit of the

  3. Aortic stenosis: From diagnosis to optimal treatment

    Directory of Open Access Journals (Sweden)

    Tavčiovski Dragan

    2008-01-01

    Full Text Available Aortic stenosis is the most frequent valvular heart disease. Aortic sclerosis is the first characteristic lesion of the cusps, which is considered today as the process similar to atherosclerosis. Progression of the disease is an active process leading to forming of bone matrix and heavily calcified stiff cusps by inflammatory cells and osteopontin. It is a chronic, progressive disease which can remain asymptomatic for a long time even in the presence of severe aortic stenosis. Proper physical examination remains an essential diagnostic tool in aortic stenosis. Recognition of characteristic systolic murmur draws attention and guides further diagnosis in the right direction. Doppler echocardiography is an ideal tool to confirm diagnosis. It is well known that exercise tests help in stratification risk of asymptomatic aortic stenosis. Serial measurements of brain natriuretic peptide during a follow-up period may help to identify the optimal time for surgery. Heart catheterization is mostly restricted to preoperative evaluation of coronary arteries rather than to evaluation of the valve lesion itself. Currently, there is no ideal medical treatment for slowing down the disease progression. The first results about the effect of ACE inhibitors and statins in aortic sclerosis and stenosis are encouraging, but there is still not enough evidence. Onset symptoms based on current ACC/AHA/ESC recommendations are I class indication for aortic valve replacement. Aortic valve can be replaced with a biological or prosthetic valve. There is a possibility of percutaneous aortic valve implantation and transapical operation for patients that are contraindicated for standard cardiac surgery.

  4. BERKELEY: ALS ring

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1993-06-15

    Everybody at Lawrence Berkeley Laboratory's Center for Beam Physics is pleased with the rapid progress in commissioning LBL's Advanced Light Source (ALS) electron storage ring, the foundation for this third-generation synchrotron radiation facility. Designed for a maximum current of 400 mA, the ALS storage ring reached 407 mA just 24 days after storing the first beam on 16 March. ALS construction as a US Department of Energy (DOE) national user facility to provide high-brightness vacuum ultra-violet and soft x-ray radiation began in October 1987. One technical requirement marking project completion was to accumulate a 50-mA current in the storage ring. The ALS passed this milestone on 24 March, a week ahead of the official deadline. Once injected, the electron beam decays quasi-exponentially primarily because of interactions with residual gas molecules in the storage-ring vacuum chamber. Eventually, when the pressure in the vacuum chamber with beam decreases toward the expected operating level of 1 nano Torr, it will only be necessary to refill the storage ring at intervals of four to eight hours. At present the vacuum is improving rapidly as surfaces are irradiated (scrubbed) by the synchrotron radiation itself. At 100 mA, beam lifetime was about one hour (9 April)

  5. Compressible Vortex Ring

    Science.gov (United States)

    Elavarasan, Ramasamy; Arakeri, Jayawant; Krothapalli, Anjaneyulu

    1999-11-01

    The interaction of a high-speed vortex ring with a shock wave is one of the fundamental issues as it is a source of sound in supersonic jets. The complex flow field induced by the vortex alters the propagation of the shock wave greatly. In order to understand the process, a compressible vortex ring is studied in detail using Particle Image Velocimetry (PIV) and shadowgraphic techniques. The high-speed vortex ring is generated from a shock tube and the shock wave, which precedes the vortex, is reflected back by a plate and made to interact with the vortex. The shadowgraph images indicate that the reflected shock front is influenced by the non-uniform flow induced by the vortex and is decelerated while passing through the vortex. It appears that after the interaction the shock is "split" into two. The PIV measurements provided clear picture about the evolution of the vortex at different time interval. The centerline velocity traces show the maximum velocity to be around 350 m/s. The velocity field, unlike in incompressible rings, contains contributions from both the shock and the vortex ring. The velocity distribution across the vortex core, core diameter and circulation are also calculated from the PIV data.

  6. BERKELEY: ALS ring

    International Nuclear Information System (INIS)

    Anon.

    1993-01-01

    Everybody at Lawrence Berkeley Laboratory's Center for Beam Physics is pleased with the rapid progress in commissioning LBL's Advanced Light Source (ALS) electron storage ring, the foundation for this third-generation synchrotron radiation facility. Designed for a maximum current of 400 mA, the ALS storage ring reached 407 mA just 24 days after storing the first beam on 16 March. ALS construction as a US Department of Energy (DOE) national user facility to provide high-brightness vacuum ultra-violet and soft x-ray radiation began in October 1987. One technical requirement marking project completion was to accumulate a 50-mA current in the storage ring. The ALS passed this milestone on 24 March, a week ahead of the official deadline. Once injected, the electron beam decays quasi-exponentially primarily because of interactions with residual gas molecules in the storage-ring vacuum chamber. Eventually, when the pressure in the vacuum chamber with beam decreases toward the expected operating level of 1 nano Torr, it will only be necessary to refill the storage ring at intervals of four to eight hours. At present the vacuum is improving rapidly as surfaces are irradiated (scrubbed) by the synchrotron radiation itself. At 100 mA, beam lifetime was about one hour (9 April)

  7. Influence of the tilt angle of Percutaneous Aortic Prosthesis on Velocity and Shear Stress Fields

    Directory of Open Access Journals (Sweden)

    Bruno Alvares de Azevedo Gomes

    Full Text Available Abstract Background: Due to the nature of the percutaneous prosthesis deployment process, a variation in its final position is expected. Prosthetic valve placement will define the spatial location of its effective orifice in relation to the aortic annulus. The blood flow pattern in the ascending aorta is related to the aortic remodeling process, and depends on the spatial location of the effective orifice. The hemodynamic effect of small variations in the angle of inclination of the effective orifice has not been studied in detail. Objective: To implement an in vitro simulation to characterize the hydrodynamic blood flow pattern associated with small variations in the effective orifice inclination. Methods: A three-dimensional aortic phantom was constructed, reproducing the anatomy of one patient submitted to percutaneous aortic valve implantation. Flow analysis was performed by use of the Particle Image Velocimetry technique. The flow pattern in the ascending aorta was characterized for six flow rate levels. In addition, six angles of inclination of the effective orifice were assessed. Results: The effective orifice at the -4° and -2° angles directed the main flow towards the anterior wall of the aortic model, inducing asymmetric and high shear stress in that region. However, the effective orifice at the +3° and +5° angles mimics the physiological pattern, centralizing the main flow and promoting a symmetric distribution of shear stress. Conclusion: The measurements performed suggest that small changes in the angle of inclination of the percutaneous prosthesis aid in the generation of a physiological hemodynamic pattern, and can contribute to reduce aortic remodeling.

  8. Altered aortic shape in bicuspid aortic valve relatives influences blood flow patterns.

    Science.gov (United States)

    Schnell, Susanne; Smith, Danielle A; Barker, Alex J; Entezari, Pegah; Honarmand, Amir R; Carr, Maria L; Malaisrie, S Chris; McCarthy, Patrick M; Collins, Jeremy; Carr, James C; Markl, Michael

    2016-11-01

    Bicuspid aortic valve (BAV) is known to exhibit familial inheritance and is associated with aortopathy and altered aortic haemodynamics. However, it remains unclear whether BAV-related aortopathy can be inherited independently of valve morphology. Four-dimensional flow magnetic resonance imaging for the in vivo assessment of thoracic aortic 3D blood flow was performed in 24 BAV relatives with trileaflet aortic valves (age = 40 ± 14 years) and 15 healthy controls (age = 37 ± 10 years). Data analysis included aortic dimensions, shape (round/gothic/cubic), and 3D blood flow characteristics (semi-quantitative vortex/helix grading and peak velocities). Cubic and gothic aortic shapes were markedly more prevalent in BAV relatives compared with controls (38 vs. 7%). Ascending aorta (AAo) vortex flow in BAV relatives was significantly increased compared with controls (grading = 1.5 ± 1.0 vs. 0.6 ± 0.9, P = 0.015). Aortic haemodynamics were influenced by aortic shape: peak velocities were reduced for gothic aortas vs. round aortas (P = 0.003); vortex flow was increased for cubic aortas in the AAo (P gothic aortas in the AAo and descending aorta (P = 0.003, P = 0.029). Logistic regression demonstrated significant associations of shape with severity of vortex flow in AAo (P < 0.001) and aortic arch (P = 0.016) in BAV relatives. BAV relatives expressed altered aortic shape and increased vortex flow despite the absence of valvular disease or aortic dilatation. These data suggest a heritable component of BAV-related aortopathy affecting aortic shape and aberrant blood flow, independent of valve morphology. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2016. For permissions please email: journals.permissions@oup.com.

  9. Combined Repair of Ascending Aortic Pseudoaneurysm and Abdominal Aortic Aneurysm in a Patient with Marfan Syndrome

    OpenAIRE

    Kokotsakis, John N.; Lioulias, Achilleas G.; Foroulis, Christophoros N.; Skouteli, Eleni Anna T.; Milonakis, Michael K.; Bastounis, Elias A.; Boulafendis, Dimitrios G.

    2003-01-01

    Pseudoaneurysms of the ascending aorta after the original inclusion/wrap technique of the Bentall procedure present a difficult surgical management problem and are associated with substantial morbidity and mortality. Patients with Marfan syndrome frequently develop aneurysms and dissections that involve multiple aortic segments. We present the case of a Marfan patient who successfully underwent repair of a giant ascending aortic pseudoaneurysm and concomitant repair of an abdominal aortic ane...

  10. The future of aortic surgery in Europe

    DEFF Research Database (Denmark)

    Czerny, Martin; Bachet, Jean; Bavaria, Joseph

    2012-01-01

    the interested reader with an overview of how aortic surgery and (perhaps more accurately) aortic medicine has evolved in Europe, and its present standing; also to provide a glimpse into the future, trying to disseminate the thoughts of a group of people actively involved in the development of aortic medicine......At least every ten years, each specialty should reflect upon its past, its present and its future, in order to be able to reconfirm the direction in which it is headed, to adopt suggestions from inside and outside and, consequently, to improve. As such, the aim of this manuscript is to provide...

  11. Mycotic Aneurysm of the Aortic Arch

    Directory of Open Access Journals (Sweden)

    Ji Hye Seo

    2014-08-01

    Full Text Available A mycotic aneurysm of the thoracic aorta is rare. We report a case of mycotic aneurysm that developed in the aortic arch. An 86-year-old man was admitted with fever and general weakness. Blood culture yielded methicillin-resistant Staphylococcus aureus. Chest X-ray showed an enlarged aortic arch, and computed tomography scan revealed an aneurysm in the aortic arch. The patient was treated only with antibiotics and not surgically. The size of the aneurysm increased rapidly, resulting in bronchial obstruction and superimposed pneumonia. The patient died of respiratory failure.

  12. Reverse extra-anatomic aortic arch debranching procedure allowing thoracic endovascular aortic repair of a chronic ascending aortic aneurysm

    Directory of Open Access Journals (Sweden)

    Ludovic Canaud, MD, PhD

    2018-06-01

    Full Text Available A 79-year-old woman was admitted with a large chronic dissecting ascending aortic aneurysm starting 5 mm distal to the ostia of the left coronary artery and ending immediately proximal to the innominate artery. A reverse extra-anatomic aortic arch debranching procedure was performed. During the same operative time, through a transapical approach, a thoracic stent graft was deployed with the proximal landing zone just distal to the coronary ostia and the distal landing zone excluding the origin of the left common carotid artery. The postoperative course was uneventful. Computed tomography at 12 months documented patent extra-anatomic aortic arch debranching and no evidence of endoleak. Keywords: Ascending aorta, Thoracic aorta, Aortic dissection, Stent graft

  13. Almost ring theory

    CERN Document Server

    2003-01-01

    This book develops thorough and complete foundations for the method of almost etale extensions, which is at the basis of Faltings' approach to p-adic Hodge theory. The central notion is that of an "almost ring". Almost rings are the commutative unitary monoids in a tensor category obtained as a quotient V-Mod/S of the category V-Mod of modules over a fixed ring V; the subcategory S consists of all modules annihilated by a fixed ideal m of V, satisfying certain natural conditions. The reader is assumed to be familiar with general categorical notions, some basic commutative algebra and some advanced homological algebra (derived categories, simplicial methods). Apart from these general prerequisites, the text is as self-contained as possible. One novel feature of the book - compared with Faltings' earlier treatment - is the systematic exploitation of the cotangent complex, especially for the study of deformations of almost algebras.

  14. The role of aortic wall CT attenuation measurements for the diagnosis of acute aortic syndromes

    International Nuclear Information System (INIS)

    Knollmann, Friedrich D.; Lacomis, Joan M.; Ocak, Iclal; Gleason, Thomas

    2013-01-01

    Objectives: To determine if measurements of aortic wall attenuation can improve the CT diagnosis of acute aortic syndromes. Methods: CT reports from a ten year period were searched for acute aortic syndromes (AAS). Studies with both an unenhanced and a contrast enhanced (CTA) series that had resulted in the diagnosis of intramural hematoma (IMH) were reviewed. Diagnoses were confirmed by medical records. The attenuation of aortic wall abnormalities was measured. The observed attenuation threshold was validated using studies from 39 new subjects with a variety of aortic conditions. Results: The term “aortic dissection” was identified in 1206, and IMH in 124 patients’ reports. IMH was confirmed in 31 patients, 21 of whom had both unenhanced and contrast enhanced images. All 21 had pathologic CTA findings, and no CTA with IMH was normal. Attenuation of the aortic wall was greater than 45 HUs on the CTA images in all patients with IMH. When this threshold was applied to the new group, sensitivity for diagnosing AAS was 100% (19/19), and specificity 94% (16/17). Addition of unenhanced images did not improve accuracy. Conclusions: Measurements of aortic wall attenuation in CTA have a high negative predictive value for the diagnosis of acute aortic syndromes

  15. Stroke Volume estimation using aortic pressure measurements and aortic cross sectional area: Proof of concept.

    Science.gov (United States)

    Kamoi, S; Pretty, C G; Chiew, Y S; Pironet, A; Davidson, S; Desaive, T; Shaw, G M; Chase, J G

    2015-08-01

    Accurate Stroke Volume (SV) monitoring is essential for patient with cardiovascular dysfunction patients. However, direct SV measurements are not clinically feasible due to the highly invasive nature of measurement devices. Current devices for indirect monitoring of SV are shown to be inaccurate during sudden hemodynamic changes. This paper presents a novel SV estimation using readily available aortic pressure measurements and aortic cross sectional area, using data from a porcine experiment where medical interventions such as fluid replacement, dobutamine infusions, and recruitment maneuvers induced SV changes in a pig with circulatory shock. Measurement of left ventricular volume, proximal aortic pressure, and descending aortic pressure waveforms were made simultaneously during the experiment. From measured data, proximal aortic pressure was separated into reservoir and excess pressures. Beat-to-beat aortic characteristic impedance values were calculated using both aortic pressure measurements and an estimate of the aortic cross sectional area. SV was estimated using the calculated aortic characteristic impedance and excess component of the proximal aorta. The median difference between directly measured SV and estimated SV was -1.4ml with 95% limit of agreement +/- 6.6ml. This method demonstrates that SV can be accurately captured beat-to-beat during sudden changes in hemodynamic state. This novel SV estimation could enable improved cardiac and circulatory treatment in the critical care environment by titrating treatment to the effect on SV.

  16. The role of aortic wall CT attenuation measurements for the diagnosis of acute aortic syndromes

    Energy Technology Data Exchange (ETDEWEB)

    Knollmann, Friedrich D., E-mail: friedrich.knollmann@ucdmc.ucdavis.edu [Department of Radiology, University of California, Davis, 4860 Y Street, Sacramento, CA 95817 (United States); Departments of Radiology and Cardiothoracic Surgery, University of Pittsburgh, 200 Lothrop Street, Pittsburgh, PA 15213 (United States); Lacomis, Joan M.; Ocak, Iclal; Gleason, Thomas [Department of Radiology, University of California, Davis, 4860 Y Street, Sacramento, CA 95817 (United States); Departments of Radiology and Cardiothoracic Surgery, University of Pittsburgh, 200 Lothrop Street, Pittsburgh, PA 15213 (United States)

    2013-12-01

    Objectives: To determine if measurements of aortic wall attenuation can improve the CT diagnosis of acute aortic syndromes. Methods: CT reports from a ten year period were searched for acute aortic syndromes (AAS). Studies with both an unenhanced and a contrast enhanced (CTA) series that had resulted in the diagnosis of intramural hematoma (IMH) were reviewed. Diagnoses were confirmed by medical records. The attenuation of aortic wall abnormalities was measured. The observed attenuation threshold was validated using studies from 39 new subjects with a variety of aortic conditions. Results: The term “aortic dissection” was identified in 1206, and IMH in 124 patients’ reports. IMH was confirmed in 31 patients, 21 of whom had both unenhanced and contrast enhanced images. All 21 had pathologic CTA findings, and no CTA with IMH was normal. Attenuation of the aortic wall was greater than 45 HUs on the CTA images in all patients with IMH. When this threshold was applied to the new group, sensitivity for diagnosing AAS was 100% (19/19), and specificity 94% (16/17). Addition of unenhanced images did not improve accuracy. Conclusions: Measurements of aortic wall attenuation in CTA have a high negative predictive value for the diagnosis of acute aortic syndromes.

  17. Aortic root reimplantation procedure: a new milestone in aortic valve-sparing operations

    Directory of Open Access Journals (Sweden)

    А. М. Чернявский

    2016-08-01

    Full Text Available Aim: Emphasis in this study was placed on clinical and functional assessment of a modified "Florida Sleeve" procedure during surgical correction of ascending aorta aneurysms with concomitant aortic insufficiency.Methods: 32 patients with an aneurysm of the ascending aorta and aortic insufficiency underwent a modified "Florida Sleeve" procedure. The average follow-up was 17 (0-60 months. The average age of patients was 57±13 (23-73 years 56±13 years.Results: The expected 4-year cumulative survival rate was 84.3%. Overall freedom from aortic insufficiency in the late period was 88.9%. Median aortic regurgitation was 1+ (1; 2. Long-term follow-up revealed no valve-associated complications.Conclusion: The aortic root reimplantation procedure enables optimal correction of the existing lesions of the aortic root without performing aortic valve replacement and demonstrates stable clinical and functional outcomes in the long-term period.Key words: aortic aneurysm; aortic valve; valve-sparing operations.FundingThe study had no sponsorship.Conflict of interestThe authors declare no conflict of interest.

  18. Compact electron storage rings

    International Nuclear Information System (INIS)

    Williams, G.P.

    1987-01-01

    There have been many recent developments in the area of compact storage rings. Such rings would have critical wavelengths of typically 10 A, achieved with beam energies of several hundreds of MeV and superconducting dipole fields of around 5 Tesla. Although the primary motivation for progress in this area is that of commercial x-ray lithography, such sources might be an attractive source for college campuses to operate. They would be useful for many programs in materials science, solid state, x-ray microscopy and other biological areas. We discuss the properties of such sources and review developments around the world, primarily in the USA, japan and W. Germany

  19. The covariant chiral ring

    Energy Technology Data Exchange (ETDEWEB)

    Bourget, Antoine; Troost, Jan [Laboratoire de Physique Théorique, École Normale Supérieure, 24 rue Lhomond, 75005 Paris (France)

    2016-03-23

    We construct a covariant generating function for the spectrum of chiral primaries of symmetric orbifold conformal field theories with N=(4,4) supersymmetry in two dimensions. For seed target spaces K3 and T{sup 4}, the generating functions capture the SO(21) and SO(5) representation theoretic content of the chiral ring respectively. Via string dualities, we relate the transformation properties of the chiral ring under these isometries of the moduli space to the Lorentz covariance of perturbative string partition functions in flat space.

  20. Vortex and source rings

    DEFF Research Database (Denmark)

    Branlard, Emmanuel Simon Pierre

    2017-01-01

    The velocity field, vector potential and velocity gradient of a vortex ring is derived in this chapter. The Biot-Savart law for the vector potential and velocity is expressed in a first section. Then, the flow is derived at specific locations: on the axis, near the axis and in the far field where...... the analogy to a doublet field is made. The following section derive the value of the vector potential and velocity field in the full domain. The expression for the velocity gradient is also provided since it may be relevant in a simulation with vortex particles and vortex rings. Most of this chapter...

  1. The Saturnian rings

    International Nuclear Information System (INIS)

    Alfven, H.

    1975-09-01

    The structure of the Saturnian rings is traditionally believed to be due to resonances caused by Mimas (and possibly other satellites). It is shown that both theoretical and observational evidence rule out this interpretation. The increased observational accuracy on one hand and the increased understanding of the cosmogonic processes on the other makes it possible to explain the structure of the ring system as a product of condensation from a partially corotating plasma. In certain respects the agreement between theory and observations is about 1%. (Auth.)

  2. RINGED ACCRETION DISKS: INSTABILITIES

    Energy Technology Data Exchange (ETDEWEB)

    Pugliese, D.; Stuchlík, Z., E-mail: d.pugliese.physics@gmail.com, E-mail: zdenek.stuchlik@physics.cz [Institute of Physics and Research Centre of Theoretical Physics and Astrophysics, Faculty of Philosophy and Science, Silesian University in Opava, Bezručovo náměstí 13, CZ-74601 Opava (Czech Republic)

    2016-04-01

    We analyze the possibility that several instability points may be formed, due to the Paczyński mechanism of violation of mechanical equilibrium, in the orbiting matter around a supermassive Kerr black hole. We consider a recently proposed model of a ringed accretion disk, made up by several tori (rings) that can be corotating or counter-rotating relative to the Kerr attractor due to the history of the accretion process. Each torus is governed by the general relativistic hydrodynamic Boyer condition of equilibrium configurations of rotating perfect fluids. We prove that the number of the instability points is generally limited and depends on the dimensionless spin of the rotating attractor.

  3. Involvement of proinflammatory S100A9/A8 in the atherocalcinosis of aortic valves

    Directory of Open Access Journals (Sweden)

    R. А. Moskalenko

    2017-04-01

    Full Text Available According to the results of the Euro-Heart Survey on Vascular Heart Disease the most common pathology is nonrheumatic aortic stenosis, it is also called as calcific aortic valve stenosis (CAVS, as in its pathogenesis the process of biomineralization of valve cusps and ring plays the main role. The aim of the work is the immunohistochemical study of mineralized tissue of aortic heart valves, which are affected by atherocalcinosis. Materials and methods. 30 samples of mineralized aortic valves (I group and 10 samples of aortic valve without evidence of biomineralization (II group -– control were studied. Immunohistochemical study of expression of collagen (Collagen I, CD68, myeloperoxidase (MPO, calgranulin A (S100A8, calgranulin B (S100A9, caspase 3 (Casp 3 and osteopontin (OPN was conducted in AV tissue of both groups. Results. In CAV tissues the fibrillar component (collagen I growths was found, but the quantitative and qualitative compositions of CD68+ circulating inflammatory cells are not significantly different from the control group. CAVs contain much more MPO+ -cells (p <0.001 in comparison to the group of AVs without biomineralization. Our data show a significant increase of the S100A9 and OPN expression in the mineralized tissue of AVs (p < 0.01. Also, a higher expression level of Casp3 and MPO was found in CAVs (p < 0.05. Comparing the first and the second groups of AVs connection between the expression of S100A8 was not determined. Conclusion. High Casp 3 expression confirms the increased level of cell elimination in the CAVs tissue, which is obviously connected with the impact of high local concentrations of S100A9. These facts can contribute to the development of pathological biomineralization of AV. Since osteopontin inhibits the hydroxyapatite formation by binding to the surface of the crystals, its hyperproduction is a counteracting factor against biomineralization in AV tissue.

  4. Dissecting aortic aneurysm in maintenance hemodialysis patients

    Directory of Open Access Journals (Sweden)

    Ounissi M

    2009-01-01

    Full Text Available The dissecting aortic aneurysm (DAA is a rare pathology that may result in fatal outcome. We report follow up of three cases of DAA patients undergoing maintenance hemo-dialysis who were managed conservatively.

  5. Traumatic aortic dissection presenting with respiratory arrest

    Directory of Open Access Journals (Sweden)

    C.C. Meyer

    2015-03-01

    Conclusion: Blunt aortic injury is a major cause of death in blunt chest trauma. Signs and symptoms of this injury are nonspecific and other injuries often take precedence, which makes a relatively difficult diagnosis even more challenging.

  6. Aortic root reoperations after pulmonary autograft implantation

    NARCIS (Netherlands)

    J.A. Bekkers (Jos); L.M.A. Klieverik (Loes Maria Anne); G. Bol-Raap (Goris); J.J.M. Takkenberg (Hanneke); A.J.J.C. Bogers (Ad)

    2010-01-01

    textabstractObjective: To report the results of aortic root reoperations after pulmonary autograft implantation. Methods: All consecutive patients in our prospective Ross research database were selected for analysis, and additional information for patients requiring reoperation was obtained from the

  7. [Aortic valve-sparing root reconstruction in Marfan syndrome].

    Science.gov (United States)

    Ogino, H; Sasaki, H; Hanafusa, Y; Hirata, M; Numata, S; Ando, M; Yagihara, T; Kitamura, S

    2002-07-01

    The outcome of aortic valve-sparing root reconstruction in Marfan syndrome was reviewed. Thirteen patients with Marfan syndrome underwent aortic valve-sparing root reconstruction for annuloaortic ectasia or aortic root dissection between 1994 and 1999. The grade of preoperative aortic regurgitation was I in 4, II in 2, III in 5, IV in 2 patients. The procedures of aortic valve-sparing were reimplantation in 7 and remodeling in 5 patients. There was no hospital and late death. Recurrence of aortic regurgitation greater than moderate grade developed in 1 patient immediately after the surgery and in the other 4 patients in the late stage. One patient of them required aortic valve replacement for it. Aortic valve-sparing root reconstruction is applicable in Marfan patients, although the indication should be cautious. Close observation is needed for recurrence of aortic regurgitation.

  8. CT diagnosis of acute aortic dissection

    International Nuclear Information System (INIS)

    Ogawa, Noriko; Kobayashi, Takeshi

    1989-01-01

    Sixteen (47.5%) of 35 patients with acute aortic dissection showed a non-opacified crescent in the aorta on an initial contrast CT. Seven of these 16 patients underwent cineangiography soon after the initial CT, and in all 7 patients, neither an intimal tear nor an intimal flap was obtained. All but one of above 16 patients were followed by CT. Mean duration of follow-up was 9.6 months. In 10 of 15 patients with non-opacified false lumen, the false lumen remained non-opacified until the last examination. Moreover, in 6 of these 10 patients, the false lumen shrunk, and in the other 3, it disappeared completely on follow-up CT. On the other hand, in remaining 5 of these 15 patients who were initially diagnosed to have non-opacified false lumen, the false lumen became opacified and enlarged in size on follow-up CT performed in the first 14 weeks. Moreover, in 4 of these 5 patients, the false lumen became opacified in the only first 6 weeks. No matter how intensive care should be paid at least for the first 6 weeks, it seems that patients with aortic dissection which have non-opacified false lumen had good prognosis in comparison to patients with ordinary aortic dissections which have opacified false lumen. We believe aortic dissection with non-opacified false lumen may consist of two type of aortic dissection, one has no intimal tear, the other has some intimal tears and a thrombosed false lumen. In conclusion, CT is the most useful modality in diagnosing acute aortic dissection. The reasons are the incidence of acute aortic dissection with non-opacified false lumen was high, patients with non-opacified false lumen had good prognosis, and it was difficult to diagnose aortic dissection with non-opacified false lumen by conventional cineangiography and/or DSA. (author)

  9. Graft infections after surgical aortic reconstructions

    OpenAIRE

    Berger, P.

    2015-01-01

    Prosthetic vascular grafts are frequently used to reconstruct (part) of the aorta. Every surgical procedure caries a certain risk for infection and when a prosthetic aortic graft is implanted, this may lead to an aortic graft infection (AGI). Endovascular techniques have gradually replaced open surgical reconstructions as first line of treatment for aorto-iliac diseases. Nowadays, open reconstructions are primarily reserved for patients unsuitable for endovascular reconstructions or for redo ...

  10. Aortic dissection. Basic aspects and endovascular management

    International Nuclear Information System (INIS)

    Jaramillo, Nicolas I; Alviar, Carlos I

    2005-01-01

    Treatment of thoracic aortic pathology is complicated by the morbidity associated to the surgical procedure and to the frailty of an elderly and difficult population. Surgical operation in this kind of population frequently bears a significant incidence of death and long-term disability. In an effort to reduce the incidence of negative outcomes, minimally invasive techniques in the form of endovascular stenting have been introduced during the past decade. The technology, originally described by Parodi, and initially designed for its use in abdominal aortic aneurysms, has been adapted for the treatment of thoracic aortic aneurysms. Furthermore, an improved understanding of the pathophysiology and the natural history of thoracic aortic disease as well as the analysis of the outcomes have facilitated our treatment decisions in terms of the timing for an appropriate intervention. Treatment of thoracic aortic dissection using endovascular Stent is one of the more recent advances in this condition and is receiving increasing attention, as it is a less invasive alternative to an open surgical repair. Although this technology is still innovative, significant improvements have been made lately in the design and deployment of the endovascular Stent-grafts. These prostheses have been increasingly used to treat aneurysms, dissections and traumatic ruptures, as well as giant penetrating ulcers and intramural hematomas of the descending thoracic aorta with good early and mid-term outcomes. The rareness, complexity and severity of the pathology and the theoretically high risk of complications should render the surgeon extremely cautious especially with young patients. Conceptually, the endo luminal treatment in the acute phase seems to be the solution and will probably become a preferred therapy while technical refinement is under way. Worldwide experience is growing and with this a better understanding of the indications and limitations of this innovative therapy will be

  11. Fusion rings and fusion ideals

    DEFF Research Database (Denmark)

    Andersen, Troels Bak

    by the so-called fusion ideals. The fusion rings of Wess-Zumino-Witten models have been widely studied and are well understood in terms of precise combinatorial descriptions and explicit generating sets of the fusion ideals. They also appear in another, more general, setting via tilting modules for quantum......This dissertation investigates fusion rings, which are Grothendieck groups of rigid, monoidal, semisimple, abelian categories. Special interest is in rational fusion rings, i.e., fusion rings which admit a finite basis, for as commutative rings they may be presented as quotients of polynomial rings...

  12. Flushing Ring for EDM

    Science.gov (United States)

    Earwood, L.

    1985-01-01

    Removing debris more quickly lowers cutting time. Operation, cutting oil and pressurized air supplied to ring placed around workpiece. Air forces oil through small holes and agitates oil as it flows over workpiece. High flow rate and agitation dislodge and remove debris. Electrical discharge removes material from workpiece faster.

  13. Sector ring accelerator ''RESATRON''

    International Nuclear Information System (INIS)

    Schwabe, E.

    1980-01-01

    Project of sector ring accelerator RESATRON is described. The curiosity of this accelerator is the second cycle of acceleration of the beam after stripping it on the foil. In such an accelerator heavy ions with a different ratio Z to A can be accelerated. (S.B.)

  14. Ring chromosome 13

    DEFF Research Database (Denmark)

    Brandt, C A; Hertz, Jens Michael; Petersen, M B

    1992-01-01

    A stillborn male child with anencephaly and multiple malformations was found to have the karyotype 46,XY,r(13) (p11q21.1). The breakpoint at 13q21.1, determined by high resolution banding, is the most proximal breakpoint ever reported in patients with ring chromosome 13. In situ hybridisation...

  15. SXLS storage ring design

    International Nuclear Information System (INIS)

    Anon.

    1991-01-01

    X-ray lithography has emerged as a strong candidate to meet the demands of ever finer linewidths on integrated circuits, particularly for linewidths less than .25 microns. Proximity printing X-ray lithography makes use of soft X-rays to shadow print an image of a mask onto a semiconductor wafer to produce integrated circuits. To generate the required X-rays in sufficient quantities to make commercial production viable, electron storage rings have been proposed as the soft X-ray sources. Existing storage rings have been used to do the initial development work and the success of these efforts has led the lithographers to request that new rings be constructed that are dedicated to X-ray lithography. As a result of a series of workshops held at BNL [10.3] which were attended by both semiconductor and accelerator scientists, the following set of zeroth order specifications' on the light and electron beam of a storage ring for X-ray lithography were developed: critical wavelength of light: λ c = 6 to 10 angstroms, white light power: P = 0.25 to 2.5 watts/mrad, horizontal collection angle per port: θ = 10 to 50 mrad, electron beam sizes: σ x ∼ σ y y ' < 1 mrad

  16. Ring magnetron ionizer

    International Nuclear Information System (INIS)

    Alessi, J.G.

    1986-01-01

    A ring magnetron D - charge exchange ionizer has been built and tested. An H - current of 500 μA was extracted with an estimated H 0 density in the ionizer of 10 12 cm -3 . This exceeds the performance of ionizers presently in use on polarized H - sources. The ionizer will soon be tested with a polarized atomic beam

  17. Algebras, rings and modules

    CERN Document Server

    Hazewinkel, Michiel; Kirichenko, V V

    Provides both the classical aspects of the theory of groups and their representations as well as a general introduction to the modern theory of representations, including the representations of quivers and finite partially ordered sets. This volume provides the theory of semiprime Noetherian semiperfect and semidistributive rings.

  18. Lattices for antiproton rings

    International Nuclear Information System (INIS)

    Autin, B.

    1984-01-01

    After a description of the constraints imposed by the cooling of Antiprotons on the lattice of the rings, the reasons which motivate the shape and the structure of these machines are surveyed. Linear and non-linear beam optics properties are treated with a special amplification to the Antiproton Accumulator. (orig.)

  19. Retrograde ascending aortic dissection during or after thoracic aortic stent graft placement: insight from the European registry on endovascular aortic repair complications

    DEFF Research Database (Denmark)

    Eggebrecht, Holger; Thompson, Matt; Rousseau, Hervé

    2009-01-01

    BACKGROUND: Single-center reports have identified retrograde ascending aortic dissection (rAAD) as a potentially lethal complication of thoracic endovascular aortic repair (TEVAR). METHODS AND RESULTS: Between 1995 and 2008, 28 centers participating in the European Registry on Endovascular Aortic...

  20. Long-Term Risk for Aortic Complications After Aortic Valve Replacement in Patients With Bicuspid Aortic Valve Versus Marfan Syndrome.

    Science.gov (United States)

    Itagaki, Shinobu; Chikwe, Joanna P; Chiang, Yuting P; Egorova, Natalia N; Adams, David H

    2015-06-09

    Bicuspid aortic valves are associated with valve dysfunction, ascending aortic aneurysm and dissection. Management of the ascending aorta at the time of aortic valve replacement (AVR) in these patients is controversial and has been extrapolated from experience with Marfan syndrome, despite the absence of comparative long-term outcome data. This study sought to assess whether the natural history of thoracic aortopathy after AVR in patients with bicuspid aortic valve disease is substantially different from that seen in patients with Marfan syndrome. In this retrospective comparison, outcomes of 13,205 adults (2,079 with bicuspid aortic valves, 73 with Marfan syndrome, and 11,053 control patients with acquired aortic valve disease) who underwent primary AVR without replacement of the ascending aorta in New York State between 1995 and 2010 were compared. The median follow-up time was 6.6 years. The long-term incidence of thoracic aortic dissection was significantly higher in patients with Marfan syndrome (5.5 ± 2.7%) compared with those with bicuspid valves (0.55 ± 0.21%) and control group patients (0.41 ± 0.08%, p Marfan syndrome (10.8 ± 4.4%) compared with those with bicuspid valves (4.8 ± 0.8%) and control group patients (1.4 ± 0.2%) (p Marfan syndrome were significantly more likely to undergo thoracic aortic surgery in late follow-up (10.4 ± 4.3%) compared with those with bicuspid valves (2.5 ± 0.6%) and control group patients (0.50 ± 0.09%) (p Marfan syndrome compared with those with bicuspid aortic valves confirm that operative management of patients with bicuspid aortic valves should not be extrapolated from Marfan syndrome and support discrete treatment algorithms for these different clinical entities. Copyright © 2015 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

  1. Aortic Dissection Type A in Alpine Skiers

    Directory of Open Access Journals (Sweden)

    Thomas Schachner

    2013-01-01

    Full Text Available Patients and Methods. 140 patients with aortic dissection type A were admitted for cardiac surgery. Seventy-seven patients experienced their dissection in the winter season (from November to April. We analyzed cases of ascending aortic dissection associated with alpine skiing. Results. In 17 patients we found skiing-related aortic dissections. Skiers were taller (180 (172–200 cm versus 175 (157–191 cm, and heavier (90 (68–125 kg versus 80 (45–110 kg, than nonskiers. An extension of aortic dissection into the aortic arch, the descending thoracic aorta, and the abdominal aorta was found in 91%, 74%, and 69%, respectively, with no significant difference between skiers and nonskiers. Skiers experienced RCA ostium dissection requiring CABG in 17.6% while this was true for 5% of nonskiers (. Hospital mortality of skiers was 6% versus 13% in nonskiers (. The skiers live at an altitude of 170 (0–853 m.a.s.l. and experience their dissection at 1602 (1185–3105; m.a.s.l. In 82% symptom start was during recreational skiing without any trauma. Conclusion. Skiing associated aortic dissection type A is usually nontraumatic. The persons affected live at low altitudes and practice an outdoor sport at unusual high altitude at cold temperatures. Postoperative outcome is good.

  2. Aortic Dissection Type A in Alpine Skiers

    Science.gov (United States)

    Schachner, Thomas; Fischler, Nikolaus; Dumfarth, Julia; Bonaros, Nikolaos; Krapf, Christoph; Schobersberger, Wolfgang; Grimm, Michael

    2013-01-01

    Patients and Methods. 140 patients with aortic dissection type A were admitted for cardiac surgery. Seventy-seven patients experienced their dissection in the winter season (from November to April). We analyzed cases of ascending aortic dissection associated with alpine skiing. Results. In 17 patients we found skiing-related aortic dissections. Skiers were taller (180 (172–200) cm versus 175 (157–191) cm, P = 0.008) and heavier (90 (68–125) kg versus 80 (45–110) kg, P = 0.002) than nonskiers. An extension of aortic dissection into the aortic arch, the descending thoracic aorta, and the abdominal aorta was found in 91%, 74%, and 69%, respectively, with no significant difference between skiers and nonskiers. Skiers experienced RCA ostium dissection requiring CABG in 17.6% while this was true for 5% of nonskiers (P = 0.086). Hospital mortality of skiers was 6% versus 13% in nonskiers (P = 0.399). The skiers live at an altitude of 170 (0–853) m.a.s.l. and experience their dissection at 1602 (1185–3105; P < 0.001) m.a.s.l. In 82% symptom start was during recreational skiing without any trauma. Conclusion. Skiing associated aortic dissection type A is usually nontraumatic. The persons affected live at low altitudes and practice an outdoor sport at unusual high altitude at cold temperatures. Postoperative outcome is good. PMID:23971024

  3. Quantification of abdominal aortic deformation after EVAR

    Science.gov (United States)

    Demirci, Stefanie; Manstad-Hulaas, Frode; Navab, Nassir

    2009-02-01

    Quantification of abdominal aortic deformation is an important requirement for the evaluation of endovascular stenting procedures and the further refinement of stent graft design. During endovascular aortic repair (EVAR) treatment, the aortic shape is subject to severe deformation that is imposed by medical instruments such as guide wires, catheters, and, the stent graft. This deformation can affect the flow characteristics and morphology of the aorta which have been shown to be elicitors for stent graft failures and be reason for reappearance of aneurysms. We present a method for quantifying the deformation of an aneurysmatic aorta imposed by an inserted stent graft device. The outline of the procedure includes initial rigid alignment of the two abdominal scans, segmentation of abdominal vessel trees, and automatic reduction of their centerline structures to one specified region of interest around the aorta. This is accomplished by preprocessing and remodeling of the pre- and postoperative aortic shapes before performing a non-rigid registration. We further narrow the resulting displacement fields to only include local non-rigid deformation and therefore, eliminate all remaining global rigid transformations. Finally, deformations for specified locations can be calculated from the resulting displacement fields. In order to evaluate our method, experiments for the extraction of aortic deformation fields are conducted on 15 patient datasets from endovascular aortic repair (EVAR) treatment. A visual assessment of the registration results and evaluation of the usage of deformation quantification were performed by two vascular surgeons and one interventional radiologist who are all experts in EVAR procedures.

  4. Propellers in Saturn's rings

    Science.gov (United States)

    Sremcevic, M.; Stewart, G. R.; Albers, N.; Esposito, L. W.

    2013-12-01

    Theoretical studies and simulations have demonstrated the effects caused by objects embedded in planetary rings. Even if the objects are too small to be directly observed, each creates a much larger gravitational imprint on the surrounding ring material. These strongly depend on the mass of the object and range from "S" like propeller-shaped structures for about 100m-sized icy bodies to the opening of circumferential gaps as in the case of the embedded moons Pan and Daphnis and their corresponding Encke and Keeler Gaps. Since the beginning of the Cassini mission many of these smaller objects (~data from Cassini Ultraviolet Imaging Spectrograph (UVIS) and Imaging Science Subsystem (ISS) experiments. We show evidence that B ring seems to harbor two distinct populations of propellers: "big" propellers covering tens of degrees in azimuth situated in the densest part of B ring, and "small" propellers in less dense inner B ring that are similar in size and shape to known A ring propellers. The population of "big" propellers is exemplified with a single object which is observed for 5 years of Cassini data. The object is seen as a very elongated bright stripe (40 degrees wide) in unlit Cassini images, and dark stripe in lit geometries. In total we report observing the feature in images at 18 different epochs between 2005 and 2010. In UVIS occultations we observe this feature as an optical depth depletion in 14 out of 93 occultation cuts at corrotating longitudes compatible with imaging data. Combining the available Cassini data we infer that the object is a partial gap located at r=112,921km embedded in the high optical depth region of the B ring. The gap moves at Kepler speed appropriate for its radial location. Radial offsets of the gap locations in UVIS occultations are consistent with an asymmetric propeller shape. The asymmetry of the observed shape is most likely a consequence of the strong surface mass density gradient, as the feature is located at an edge between

  5. Geometric Deformations of the Thoracic Aorta and Supra-Aortic Arch Branch Vessels Following Thoracic Endovascular Aortic Repair.

    Science.gov (United States)

    Ullery, Brant W; Suh, Ga-Young; Hirotsu, Kelsey; Zhu, David; Lee, Jason T; Dake, Michael D; Fleischmann, Dominik; Cheng, Christopher P

    2018-04-01

    To utilize 3-D modeling techniques to better characterize geometric deformations of the supra-aortic arch branch vessels and descending thoracic aorta after thoracic endovascular aortic repair. Eighteen patients underwent endovascular repair of either type B aortic dissection (n = 10) or thoracic aortic aneurysm (n = 8). Computed tomography angiography was obtained pre- and postprocedure, and 3-D geometric models of the aorta and supra-aortic branch vessels were constructed. Branch angle of the supra-aortic branch vessels and curvature metrics of the ascending aorta, aortic arch, and stented thoracic aortic lumen were calculated both at pre- and postintervention. The left common carotid artery branch angle was lower than the left subclavian artery angles preintervention ( P Supra-aortic branch vessel angulation remains relatively static when proximal landing zones are distal to the left common carotid artery.

  6. FUZZY RINGS AND ITS PROPERTIES

    Directory of Open Access Journals (Sweden)

    Karyati Karyati

    2017-01-01

      One of algebraic structure that involves a binary operation is a group that is defined  an un empty set (classical with an associative binary operation, it has identity elements and each element has an inverse. In the structure of the group known as the term subgroup, normal subgroup, subgroup and factor group homomorphism and its properties. Classical algebraic structure is developed to algebraic structure fuzzy by the researchers as an example semi group fuzzy and fuzzy group after fuzzy sets is introduced by L. A. Zadeh at 1965. It is inspired of writing about semi group fuzzy and group of fuzzy, a research on the algebraic structure of the ring is held with reviewing ring fuzzy, ideal ring fuzzy, homomorphism ring fuzzy and quotient ring fuzzy with its properties. The results of this study are obtained fuzzy properties of the ring, ring ideal properties fuzzy, properties of fuzzy ring homomorphism and properties of fuzzy quotient ring by utilizing a subset of a subset level  and strong level  as well as image and pre-image homomorphism fuzzy ring.   Keywords: fuzzy ring, subset level, homomorphism fuzzy ring, fuzzy quotient ring

  7. Aortopathy in Congenital Heart Disease in Adults: Aortic Dilatation with Decreased Aortic Elasticity that Impacts Negatively on Left Ventricular Function.

    Science.gov (United States)

    Niwa, Koichiro

    2013-04-01

    Bicuspid aortic valve and/or coarctation of the aorta are consistently associated with ascending aortic and para-coarctation medial abnormalities. Medial abnormalities in the ascending aorta are prevalent in other types of patients with a variety of forms congenital heart disease (CHD), such as single ventricle, persistent truncus arteriosus, transposition of the great arteries, hypoplastic left heart syndrome, tetralogy of Fallot. These abnormalities encompass a wide age range, and may predispose to dilatation, aneurysm, and rupture that necessitates aortic valve and root surgery. This dilatation can develop in CHD patients without stenotic region. These CHDs exhibit ongoing dilatation of the aortic root and reduced aortic elasticity and increased aortic stiffness that may relate to intrinsic properties of the aortic root. The concept of aortic dilatation is shifting a paradigm of aortic dilatation, as so called post stenotic dilatation, to primary intrinsic aortopahy. These aortic dilatation and increased stiffness can induce aortic aneurysm, rupture of the aorta and aortic regurgitation, but also provoke left ventricular hypertrophy, reduced coronary artery flow and left ventricular failure. We can recognize this association of aortic pathophysiological abnormality, aortic dilation and aorto-left ventricular interaction as a new clinical entity: "aortopathy".

  8. Aortic events in a nationwide Marfan syndrome cohort

    DEFF Research Database (Denmark)

    Groth, Kristian A; Krag, Kirstine Stochholm; Hove, Hanne

    2017-01-01

    BACKGROUND: Marfan syndrome is associated with morbidity and mortality due to aortic dilatation and dissection. Preventive aortic root replacement has been the standard treatment in Marfan syndrome patients with aortic dilatation. In this study, we present aortic event data from a nationwide Marfan...... syndrome cohort. METHOD: The nationwide cohort of Danish Marfan syndrome patients was established from the Danish National Patient Registry and the Cause of Death Register, where we retrieved information about aortic surgery and dissections. We associated aortic events with age, sex, and Marfan syndrome...

  9. [Aortic elastic properties and its clinical significance in intracranial aneurysms].

    Science.gov (United States)

    Pu, Zhao-xia; You, Xiang-dong; Weng, Wen-chao; Wang, Jian-an; Shi, Jian

    2011-09-01

    To investigate the aortic elastic properties and its clinical significance in intracranial aneurysms (IAs). One hundred and seven IAs patients (57 with hypertension) and 108 healthy subjects were recruited. The internal aortic diameters in systole and diastole were measured by the M-mode echocardiography, the aortic elasticity indexes were calculated and compared. The aortic distensibility (DIS) was lower and the aortic stiffness index (SI) was higher in IAs patients than those in controls (both P IAs patients with hypertension (IAs-HP) than those in IAs with no hypertension (P IAs patients and hypertension is closely related to the severity of aortic elasticity.

  10. Aortic annulus and ascending aorta: Comparison of preoperative and periooperative measurement in patients with aortic stenosis

    International Nuclear Information System (INIS)

    Smid, Michal; Ferda, Jiri; Baxa, Jan; Cech, Jakub; Hajek, Tomas; Kreuzberg, Boris; Rokyta, Richard

    2010-01-01

    Background: Precise determination of the aortic annulus size constitutes an integral part of the preoperative evaluation prior to aortic valve replacement. It enables the estimation of the size of prosthesis to be implanted. Knowledge of the size of the ascending aorta is required in the preoperative analysis and monitoring of its dilation enables the precise timing of the operation. Our goal was to compare the precision of measurement of the aortic annulus and ascending aorta using magnetic resonance (MR), multidetector-row computed tomography (MDCT), transthoracic echocardiography (TTE), and transoesophageal echocardiography (TEE) in patients with degenerative aortic stenosis. Methods and results: A total of 15 patients scheduled to have aortic valve replacement were enrolled into this prospective study. TTE was performed in all patients and was supplemented with TEE, CT and MR in the majority of patients. The values obtained were compared with perioperative measurements. For the measurement of aortic annulus, MR was found to be the most precise technique, followed by MDCT, TTE, and TEE. For the measurement of ascending aorta, MR again was found to be the most precise technique, followed by MDCT, TEE, and TTE. Conclusion: In our study, magnetic resonance was found to be the most precise technique for the measurement of aortic annulus and ascending aorta in patients with severe degenerative aortic stenosis.

  11. Systematic review of the outcome of aortic valve replacement in patients with aortic stenosis

    NARCIS (Netherlands)

    Sharma, Umesh C.; Barenbrug, Paul; Pokharel, Saraswati; Dassen, Willem R. M.; Pinto, Yigal M.; Maessen, Jos G.

    2004-01-01

    BACKGROUND: After the establishment of aortic valve replacement procedure for aortic stenosis, there are heterogeneous studies and varying reports on outcome. An analysis that compares individual studies to summarize the overall effect is still lacking. This study systematically analyzes the change

  12. Aortic stiffness and diameter predict progressive aortic dilatation in patients with Marfan syndrome

    NARCIS (Netherlands)

    Nollen, Gijs J.; Groenink, Maarten; Tijssen, Jan G. P.; van der Wall, Ernst E.; Mulder, Barbara J. M.

    2004-01-01

    Aim Patients with Marfan syndrome may develop dissection due to progressive dilatation in the entire aorta, which is not always predictable by mere anatomic assessment of the aortic diameter, especially of the descending aorta. The aim of this study was to identify the predictive value of aortic

  13. Transcatheter aortic valve implantation: emerging role in poor left ventricular function severe aortic stenosis?

    Directory of Open Access Journals (Sweden)

    K. M. John Chan

    2014-01-01

    Full Text Available Transcatheter aortic valve implantation (TAVI has become an established treatment option for high risk elderly patients with symptomatic severe aortic stenosis. Its role in less high risk patients is being evaluated in clinical trials. Patients with severely impaired left ventricular function may be another group who may benefit from this emerging percutaneous treatment option.

  14. Effect of candesartan treatment on left ventricular remodeling after aortic valve replacement for aortic stenosis

    DEFF Research Database (Denmark)

    Dahl, Jordi S; Videbaek, Lars; Poulsen, Mikael K

    2010-01-01

    In hypertension, angiotensin receptor blockers can augment regression of left ventricular (LV) hypertrophy. It is not known whether this also is the case after aortic valve replacement (AVR) for severe aortic stenosis (AS). To test the hypothesis that treatment with candesartan in addition to con...

  15. Inorganic glass ceramic slip rings

    Science.gov (United States)

    Glossbrenner, E. W.; Cole, S. R.

    1972-01-01

    Prototypes of slip rings have been fabricated from ceramic glass, a material which is highly resistant to deterioration due to high temperature. Slip ring assemblies were not structurally damaged by mechanical tests and performed statisfactorily for 200 hours.

  16. Uniquely Strongly Clean Group Rings

    Institute of Scientific and Technical Information of China (English)

    WANG XIU-LAN

    2012-01-01

    A ring R is called clean if every element is the sum of an idempotent and a unit,and R is called uniquely strongly clean (USC for short) if every element is uniquely the sum of an idempotent and a unit that commute.In this article,some conditions on a ring R and a group G such that RG is clean are given.It is also shown that if G is a locally finite group,then the group ring RG is USC if and only if R is USC,and G is a 2-group.The left uniquely exchange group ring,as a middle ring of the uniquely clean ring and the USC ring,does not possess this property,and so does the uniquely exchange group ring.

  17. Application of thoracic endovascular aortic repair (TEVAR) in treating dwarfism with Stanford B aortic dissection

    Science.gov (United States)

    Qiu, Jian; Cai, Wenwu; Shu, Chang; Li, Ming; Xiong, Qinggen; Li, Quanming; Li, Xin

    2018-01-01

    Abstract Rationale: To apply thoracic endovascular aortic repair (TEVAR) to treat dwarfism complicated with Stanford B aortic dissection. Patient concerns: In this report, we presented a 63-year-old male patient of dwarfism complicated with Stanford B aortic dissection successfully treated with TEVAR. Diagnoses: He was diagnosed with dwarfism complicated with Stanford B aortic dissection. Interventions: After conservative treatment, the male patient underwent TEVAR at 1 week after hospitalization. After operation, he presented with numbness and weakness of his bilateral lower extremities, and these symptoms were significantly mitigated after effective treatment. At 1- and 3-week after TEVAR, the aorta status was maintained stable and restored. Outcomes: The patient obtained favorable clinical prognosis and was smoothly discharged. During subsequent follow-up, he remained physically stable. Lessons: TEVAR is probably an option for treating dwarfism complicated with Stanford B aortic dissection, which remains to be validated by subsequent studies with larger sample size. PMID:29703033

  18. Ring closure in actin polymers

    Energy Technology Data Exchange (ETDEWEB)

    Sinha, Supurna, E-mail: supurna@rri.res.in [Raman Research Institute, Bangalore 560080 (India); Chattopadhyay, Sebanti [Doon University, Dehradun 248001 (India)

    2017-03-18

    We present an analysis for the ring closure probability of semiflexible polymers within the pure bend Worm Like Chain (WLC) model. The ring closure probability predicted from our analysis can be tested against fluorescent actin cyclization experiments. We also discuss the effect of ring closure on bend angle fluctuations in actin polymers. - Highlights: • Ring closure of biopolymers. • Worm like chain model. • Predictions for experiments.

  19. Design of low energy ring(s)

    CERN Document Server

    Lachaize, Antoine

    During the last two years, several upgrades of the initial baseline scenario were studied with the aim of increasing the average intensity of ion beams in the accelerator chain of the Beta Beam complex. This is the reason why the Rapid Cycling Synchrotron (RCS) specifications were reconsidered many times [1], [2], [3].General considerations on the optical design were presented at the Beta Beam Task Meetings held at CERN and at Saclay in 2005 [4]. More detailed beam optics studies were performed during the next months. Lattices, RF system parameters, multi-turn injection scheme, fast extraction, closed orbit correction and chromaticity correction systems were proposed for different versions of the RCS [5], [6], [7].Finally, the RCS specifications have stabilized in November 2006 after the fourth Beta Beam Task Meeting when it was decided to fix the maximum magnetic rigidity of ion beams to 14.47 T.m (3.5 GeV equivalent proton energy) and to adopt a ring physical radius of 40 m in order to facilitate injectio...

  20. Use of cardiovascular magnetic resonance imaging for TAVR assessment in patients with bioprosthetic aortic valves: Comparison with computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Quail, Michael A., E-mail: m.quail@ucl.ac.uk [Centre for Cardiovascular Imaging, UCL Institute of Cardiovascular Science and Great Ormond Street Hospital for Children, London (United Kingdom); Nordmeyer, Johannes [Department of Congenital Heart Disease and Paediatric Cardiology, Deutsches Herzzentrum Berlin, Berlin (Germany); Schievano, Silvia [Centre for Cardiovascular Imaging, UCL Institute of Cardiovascular Science and Great Ormond Street Hospital for Children, London (United Kingdom); Reinthaler, Markus; Mullen, Michael J. [The Heart Hospital, University College Hospital and Institute of Cardiovascular Sciences, UCL, 16-18 Westmoreland Street, London (United Kingdom); Taylor, Andrew M. [Centre for Cardiovascular Imaging, UCL Institute of Cardiovascular Science and Great Ormond Street Hospital for Children, London (United Kingdom)

    2012-12-15

    Purpose: Transcatheter aortic valve replacement (TAVR) has been successfully used to treat patients with failing aortic bioprostheses. Computed tomography (CT) is the usual method of pre-procedural imaging for TAVR in the native position; however, the optimal modality for valve-in-valve procedures has not been established. CT can assess intracardiac anatomy and is superior to cardiovascular magnetic resonance (CMR) in the assessment of coronary artery disease. However, CMR can provide superior haemodynamic information, does not carry the risk of ionising radiation, and may be performed without contrast in patients with renal insufficiency. In this study, we compared CT and CMR for the evaluation of TAVR in a small cohort of patients with existing aortic bioprostheses. Materials and methods: 21 patients with aortic bioprostheses were prospectively evaluated by CT and CMR, as pre-assessment for TAVR; agreement between measurements of aortic geometries was assessed. Results: 16/21 patients had aortic bioprostheses constructed with a metal ring, and 5/21 patients had a metal strut construction. Patients with metal struts had significant metal-artefact on CMR, which compromised image quality in this region. There was good agreement between CT and CMR measurements of aortic geometry. The mean difference (d) in annulus area-derived diameter was 0.5 mm (95% limits of agreement [L.A] 4.2 mm). There was good agreement between modalities for the cross-sectional area of the sinuses of valsalva (d 0.5 cm{sup 2}, L.A 1.4 cm{sup 2}), sinotubular junction (d 0.9 cm{sup 2}, L.A 1.5 cm{sup 2}), and ascending aorta (d 0.6 cm{sup 2}, L.A 1.4 cm{sup 2}). In patients without metal struts, the left coronary artery height d was 0.7 mm and L.A 2.8 mm. Conclusions: Our analysis shows that CMR and CT measurements of aortic geometry show good agreement, including measurement of annulus size and coronary artery location, and thus provide the necessary anatomical information for valve

  1. Use of cardiovascular magnetic resonance imaging for TAVR assessment in patients with bioprosthetic aortic valves: Comparison with computed tomography

    International Nuclear Information System (INIS)

    Quail, Michael A.; Nordmeyer, Johannes; Schievano, Silvia; Reinthaler, Markus; Mullen, Michael J.; Taylor, Andrew M.

    2012-01-01

    Purpose: Transcatheter aortic valve replacement (TAVR) has been successfully used to treat patients with failing aortic bioprostheses. Computed tomography (CT) is the usual method of pre-procedural imaging for TAVR in the native position; however, the optimal modality for valve-in-valve procedures has not been established. CT can assess intracardiac anatomy and is superior to cardiovascular magnetic resonance (CMR) in the assessment of coronary artery disease. However, CMR can provide superior haemodynamic information, does not carry the risk of ionising radiation, and may be performed without contrast in patients with renal insufficiency. In this study, we compared CT and CMR for the evaluation of TAVR in a small cohort of patients with existing aortic bioprostheses. Materials and methods: 21 patients with aortic bioprostheses were prospectively evaluated by CT and CMR, as pre-assessment for TAVR; agreement between measurements of aortic geometries was assessed. Results: 16/21 patients had aortic bioprostheses constructed with a metal ring, and 5/21 patients had a metal strut construction. Patients with metal struts had significant metal-artefact on CMR, which compromised image quality in this region. There was good agreement between CT and CMR measurements of aortic geometry. The mean difference (d) in annulus area-derived diameter was 0.5 mm (95% limits of agreement [L.A] 4.2 mm). There was good agreement between modalities for the cross-sectional area of the sinuses of valsalva (d 0.5 cm 2 , L.A 1.4 cm 2 ), sinotubular junction (d 0.9 cm 2 , L.A 1.5 cm 2 ), and ascending aorta (d 0.6 cm 2 , L.A 1.4 cm 2 ). In patients without metal struts, the left coronary artery height d was 0.7 mm and L.A 2.8 mm. Conclusions: Our analysis shows that CMR and CT measurements of aortic geometry show good agreement, including measurement of annulus size and coronary artery location, and thus provide the necessary anatomical information for valve-in-valve TAVR planning. However

  2. Fusion Rings for Quantum Groups

    DEFF Research Database (Denmark)

    Andersen, Henning Haahr; Stroppel, Catharina

    2012-01-01

    We study the fusion rings of tilting modules for a quantum group at a root of unity modulo the tensor ideal of negligible tilting modules. We identify them in type A with the combinatorial rings from [12] and give a similar description of the sp2n-fusion ring in terms of noncommutative symmetric...

  3. RINGED ACCRETION DISKS: EQUILIBRIUM CONFIGURATIONS

    Energy Technology Data Exchange (ETDEWEB)

    Pugliese, D.; Stuchlík, Z., E-mail: d.pugliese.physics@gmail.com, E-mail: zdenek.stuchlik@physics.cz [Institute of Physics and Research Centre of Theoretical Physics and Astrophysics, Faculty of Philosophy and Science, Silesian University in Opava, Bezručovo náměstí 13, CZ-74601 Opava (Czech Republic)

    2015-12-15

    We investigate a model of a ringed accretion disk, made up by several rings rotating around a supermassive Kerr black hole attractor. Each toroid of the ringed disk is governed by the general relativity hydrodynamic Boyer condition of equilibrium configurations of rotating perfect fluids. Properties of the tori can then be determined by an appropriately defined effective potential reflecting the background Kerr geometry and the centrifugal effects. The ringed disks could be created in various regimes during the evolution of matter configurations around supermassive black holes. Therefore, both corotating and counterrotating rings have to be considered as being a constituent of the ringed disk. We provide constraints on the model parameters for the existence and stability of various ringed configurations and discuss occurrence of accretion onto the Kerr black hole and possible launching of jets from the ringed disk. We demonstrate that various ringed disks can be characterized by a maximum number of rings. We present also a perturbation analysis based on evolution of the oscillating components of the ringed disk. The dynamics of the unstable phases of the ringed disk evolution seems to be promising in relation to high-energy phenomena demonstrated in active galactic nuclei.

  4. Ring Confidential Transactions

    Directory of Open Access Journals (Sweden)

    Shen Noether

    2016-12-01

    Full Text Available This article introduces a method of hiding transaction amounts in the strongly decentralized anonymous cryptocurrency Monero. Similar to Bitcoin, Monero is a cryptocurrency which is distributed through a proof-of-work “mining” process having no central party or trusted setup. The original Monero protocol was based on CryptoNote, which uses ring signatures and one-time keys to hide the destination and origin of transactions. Recently the technique of using a commitment scheme to hide the amount of a transaction has been discussed and implemented by Bitcoin Core developer Gregory Maxwell. In this article, a new type of ring signature, A Multilayered Linkable Spontaneous Anonymous Group signature is described which allows one to include a Pedersen Commitment in a ring signature. This construction results in a digital currency with hidden amounts, origins and destinations of transactions with reasonable efficiency and verifiable, trustless coin generation. The author would like to note that early drafts of this were publicized in the Monero Community and on the #bitcoin-wizards IRC channel. Blockchain hashed drafts are available showing that this work was started in Summer 2015, and completed in early October 2015. An eprint is also available at http://eprint.iacr.org/2015/1098.

  5. Automated Normalized Cut Segmentation of Aortic Root in CT Angiography

    NARCIS (Netherlands)

    Elattar, Mustafa; Wiegerinck, Esther; Planken, Nils; VanBavel, Ed; van Assen, Hans; Baan, Jan Jr; Marquering, Henk

    2014-01-01

    Transcatheter Aortic Valve Implantation (TAVI) is a new minimal-invasive intervention for implanting prosthetic valves in patients with aortic stenosis. This procedure is associated with adverse effects like paravalvular leakage, stroke, and coronary obstruction. Accurate automated sizing for

  6. Quantification of aortic regurgitation by magnetic resonance velocity mapping

    DEFF Research Database (Denmark)

    Søndergaard, Lise; Lindvig, K; Hildebrandt, P

    1993-01-01

    The use of magnetic resonance (MR) velocity mapping in the quantification of aortic valvular blood flow was examined in 10 patients with angiographically verified aortic regurgitation. MR velocity mapping succeeded in identifying and quantifying the regurgitation in all patients, and the regurgit......The use of magnetic resonance (MR) velocity mapping in the quantification of aortic valvular blood flow was examined in 10 patients with angiographically verified aortic regurgitation. MR velocity mapping succeeded in identifying and quantifying the regurgitation in all patients...

  7. Hybrid treatment of aortic arch disease

    Science.gov (United States)

    Metzger, Patrick Bastos; Rossi, Fabio Henrique; Moreira, Samuel Martins; Issa, Mario; Izukawa, Nilo Mitsuru; Dinkhuysen, Jarbas J.; Spina Neto, Domingos; Kambara, Antônio Massamitsu

    2014-01-01

    Introduction The management of thoracic aortic disease involving the ascending aorta, aortic arch and descending thoracic aorta are technically challenging and is an area in constant development and innovation. Objective To analyze early and midterm results of hybrid treatment of arch aortic disease. Methods Retrospective study of procedures performed from January 2010 to December 2012. The end points were the technical success, therapeutic success, morbidity and mortality, neurologic outcomes, the rate of endoleaks and reinterventions. Results A total of 95 patients treated for thoracic aortic diseases in this period, 18 underwent hybrid treatment and entered in this study. The average ages were 62.3 years. The male was present in 66.7%. The technical and therapeutic success was 94.5% e 83.3%. The perioperative mortality rate of 11.1%. There is any death during one-year follow- up. The reoperation rates were 16.6% due 2 cases of endoleak Ia and one case of endoleak II. There is any occlusion of anatomic or extra anatomic bypass during follow up. Conclusion In our study, the hybrid treatment of aortic arch disease proved to be a feasible alternative of conventional surgery. The therapeutic success rates and re- interventions obtained demonstrate the necessity of thorough clinical follow-up of these patients in a long time. PMID:25714205

  8. Fusion Rings for Quantum Groups

    DEFF Research Database (Denmark)

    Andersen, Henning Haahr; Stroppel, Catharina

    2014-01-01

    We study the fusion rings of tilting modules for a quantum group at a root of unity modulo the tensor ideal of negligible tilting modules. We identify them in type A with the combinatorial rings from Korff, C., Stroppel, C.: The sl(ˆn)k-WZNW fusion ring: a combinato-rial construction...... and a realisation as quotient of quantum cohomology. Adv. Math. 225(1), 200–268, (2010) and give a similar description of the sp2n-fusion ring in terms of non-commutative symmetric functions. Moreover we give a presentation of all fusion rings in classical types as quotients of polynomial rings. Finally we also...... compute the fusion rings for type G2....

  9. Impact of bicuspid aortic valve on complications and death in infective endocarditis of native aortic valves.

    Science.gov (United States)

    Kahveci, Gokhan; Bayrak, Fatih; Pala, Selcuk; Mutlu, Bulent

    2009-01-01

    We retrospectively investigated the impact of bicuspid aortic valve on the prognosis of patients who had definite infective endocarditis of the native aortic valve.Of 51 patients, a bicuspid aortic valve was present in 22 (43%); the other 29 had tricuspid aortic valves. On average, the patients who had bicuspid valves were younger than those who had tricuspid valves. Patients with a tricuspid valve had larger left atrial diameters and were more likely to have severe mitral regurgitation.Periannular complications, which we detected in 19 patients (37%), were much more common in the patients who had a bicuspid valve (64% vs 17%, P = 0.001). The presence of a bicuspid valve was the only significant independent predictor of periannular complications. The in-hospital mortality rate in the bicuspid group was lower than that in the tricuspid group; however, this figure did not reach statistical significance (9% vs 24%, P = 0.15). In multivariate analysis, left atrial diameter was the only independent predictor associated with an increased risk of death (hazard ratio, 2.19; 95% confidence interval, 1.1-4.5; P = 0.031).In our study, patients with infective endocarditis in a bicuspid aortic valve were younger and had a higher incidence of periannular complications. Although a worse prognosis has been reported previously, we found that infective endocarditis in a native bicuspid aortic valve is not likely to increase the risk of death in comparison with infective endocarditis in native tricuspid aortic valves.

  10. Molecular-level characterization of elastin-like constructs and human aortic elastin

    DEFF Research Database (Denmark)

    Heinz, Andrea; Schräder, Christoph U; Baud, Stéphanie

    2014-01-01

    This study aimed to characterize the structures of two elastin-like constructs, one composed of a cross-linked elastin-like polypeptide and the other one of cross-linked tropoelastin, and native aortic elastin. The structures of the insoluble materials and human aortic elastin were investigated...... quantification revealed that the cross-linking degree of the two in vitro cross-linked materials was significantly lower than that of native elastin. Molecular dynamics simulations were performed, based on molecular species identified in the samples, to follow the formation of elastin cross-links. The results...... provide evidence for the significance of the GVGTP hinge region of domain 23 for the formation of elastin cross-links. Overall, this work provides important insight into structural similarities and differences between elastin-like constructs and native elastin. Furthermore, it represents a step toward...

  11. Total Endovascular Aortic Repair in a Patient with Marfan Syndrome.

    Science.gov (United States)

    Amako, Mau; Spear, Rafaëlle; Clough, Rachel E; Hertault, Adrien; Azzaoui, Richard; Martin-Gonzalez, Teresa; Sobocinski, Jonathan; Haulon, Stéphan

    2017-02-01

    The aim of this study is to describe a total endovascular aortic repair with branched and fenestrated endografts in a young patient with Marfan syndrome and a chronic aortic dissection. Open surgery is the gold standard to treat aortic dissections in patients with aortic disease and Marfan syndrome. In 2000, a 38-year-old man with Marfan syndrome underwent open ascending aorta repair for an acute type A aortic dissection. One year later, a redo sternotomy was performed for aortic valve replacement. In 2013, the patient presented with endocarditis and pulmonary infection, which necessitated tracheostomy and temporary dialysis. In 2014, the first stage of the endovascular repair was performed using an inner branched endograft to exclude a 77-mm distal arch and descending thoracic aortic aneurysm. In 2015, a 63-mm thoracoabdominal aortic aneurysm was excluded by implantation of a 4-fenestrated endograft. Follow-up after both endovascular repairs was uneventful. Total aortic endovascular repair was successfully performed to treat a patient with arch and thoraco-abdominal aortic aneurysm associated with chronic aortic dissection and Marfan syndrome. The postoperative images confirmed patency of the endograft and its branches, and complete exclusion of the aortic false lumen. Endovascular repair is a treatment option in patients with connective tissue disease who are not candidates for open surgery. Long-term follow-up is required to confirm these favorable early outcomes. Copyright © 2016 Elsevier Inc. All rights reserved.

  12. Aortic valve replacement and the stentless Freedom SOLO valve

    NARCIS (Netherlands)

    Wollersheim, L.W.L.M.

    2016-01-01

    Aortic valve stenosis has become the most prevalent valvular heart disease in Europe and North America, and is generally caused by age-related calcification of the aortic valve. For most patients, severe symptomatic aortic stenosis needs effective mechanical relief in the form of valve replacement

  13. Intermittent, Non Cyclic Severe Mechanical Aortic Valve Regurgitation

    Science.gov (United States)

    Choi, Jong Hyun; Song, Seunghwan; Lee, Myung-Yong

    2013-01-01

    Mechanical aortic prosthesis dysfunction can result from thrombosis or pannus formation. We describe an unusual case of intermittent, non cyclic mechanical aortic prosthesis dysfunction due to pannus formation with thrombus in the absence of systolic restriction of disk excursion, that presented with intermittent severe aortic regurgitation. PMID:24459568

  14. Aortic microcalcification is associated with elastin fragmentation in Marfan syndrome

    NARCIS (Netherlands)

    Wanga, Shaynah; Hibender, Stijntje; Ridwan, Yanto; van Roomen, Cindy; Vos, Mariska; van der Made, Ingeborg; van Vliet, Nicole; Franken, Romy; van Riel, Luigi Amjg; Groenink, Maarten; Zwinderman, Aeilko H.; Mulder, Barbara Jm; de Vries, Carlie Jm; Essers, Jeroen; de Waard, Vivian

    2017-01-01

    Marfan syndrome (MFS) is a connective tissue disorder in which aortic rupture is the major cause of death. MFS patients with an aortic diameter below the advised limit for prophylactic surgery ( <5 cm) may unexpectedly experience an aortic dissection or rupture, despite yearly monitoring. Hence,

  15. Challenging Friesian horse diseases : aortic rupture and megaesophagus

    NARCIS (Netherlands)

    Ploeg, M.

    2015-01-01

    Aortic rupture is quite rare in Warmblood horses and is best known as an acute and fatal rupture of the aortic root in older breeding stallions. It has now become clear that aortic rupture, which is diagnosed around an age of 4 years, is more frequent in the Friesian breed than in others. The high

  16. Aortic regurgitation after valve-sparing aortic root replacement: modes of failure.

    Science.gov (United States)

    Oka, Takanori; Okita, Yutaka; Matsumori, Masamichi; Okada, Kenji; Minami, Hitoshi; Munakata, Hiroshi; Inoue, Takeshi; Tanaka, Akiko; Sakamoto, Toshihito; Omura, Atsushi; Nomura, Takuo

    2011-11-01

    Despite the positive clinical results of valve-sparing aortic root replacement, little is known about the causes of reoperations and the modes of failure. From October 1999 to June 2010, 101 patients underwent valve-sparing aortic root replacement using the David reimplantation technique. The definition of aortic root repair failure included the following: (1) intraoperative conversion to the Bentall procedure; (2) reoperation performed because of aortic regurgitation; and (3) aortic regurgitation equal to or greater than a moderate degree at the follow-up. Sixteen patients were considered to have repair failure. Three patients required intraoperative conversion to valve replacement, 3 required reoperation within 3 months, and another 8 required reoperation during postoperative follow-up. At initial surgery 5 patients had moderate to severe aortic regurgitation, 6 patients had acute aortic dissections, 3 had Marfan syndrome, 2 had status post Ross operations, 3 had bicuspid aortic valves, and 1 had aortitis. Five patients had undergone cusp repair, including Arantius plication in 3 and plication at the commissure in 2. The causes of early failure in 6 patients included cusp perforation (3), cusp prolapse (3), and severe hemolysis (1). The causes of late failure in 10 patients included cusp prolapse (4), commissure dehiscence (3), torn cusp (2), and cusp retraction (1). Patients had valve replacements at a mean of 23 ± 20.9 months after reimplantation and survived. Causes of early failure after valve-sparing root replacement included technical failure, cusp lesions, and steep learning curve. Late failure was caused by aortic root wall degeneration due to gelatin-resorcin-formalin glue, cusp degeneration, or progression of cusp prolapse. Copyright © 2011 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

  17. Tree Rings: Timekeepers of the Past.

    Science.gov (United States)

    Phipps, R. L.; McGowan, J.

    One of a series of general interest publications on science issues, this booklet describes the uses of tree rings in historical and biological recordkeeping. Separate sections cover the following topics: dating of tree rings, dating with tree rings, tree ring formation, tree ring identification, sample collections, tree ring cross dating, tree…

  18. Dissection of Retroesophageal Aortic Diverticulum and Descending Aorta in a Patient with Right Aortic Arch: Magnetic Resonance Demonstration

    International Nuclear Information System (INIS)

    Ko, S.-F.; Ng, S.-H.; Fu, Morgan; Lo, P.-H.; Cheng, Y.-F.; Lee, T.-Y.

    1996-01-01

    An acute aortic dissection involved the retroesophageal aortic diverticulum (RAD) and descending thoracic aorta in a patient with right aortic arch. The RAD, which was separated into false and true lumens by an intimal flap-the classic diagnostic sign of aortic dissection-was overlooked on transesophageal echocardiography and computed tomography but was clearly depicted on magnetic resonance imaging (MRI). It was found that MRI can delineate the anatomy of a congenital arch anomaly complicated by great vessels disease

  19. Microarray analysis to identify the similarities and differences of pathogenesis between aortic occlusive disease and abdominal aortic aneurysm.

    Science.gov (United States)

    Wang, Guofu; Bi, Lechang; Wang, Gaofeng; Huang, Feilai; Lu, Mingjing; Zhu, Kai

    2018-06-01

    Objectives Expression profile of GSE57691 was analyzed to identify the similarities and differences between aortic occlusive disease and abdominal aortic aneurysm. Methods The expression profile of GSE57691 was downloaded from Gene Expression Omnibus database, including 20 small abdominal aortic aneurysm samples, 29 large abdominal aortic aneurysm samples, 9 aortic occlusive disease samples, and 10 control samples. Using the limma package in R, the differentially expressed genes were screened. Followed by enrichment analysis was performed for the differentially expressed genes using database for annotation, visualization, and integrated discovery online tool. Based on string online tool and Cytoscape software, protein-protein interaction network and module analyses were carried out. Moreover, integrated TF platform database and Cytoscape software were used for constructing transcriptional regulatory networks. Results As a result, 1757, 354, and 396 differentially expressed genes separately were identified in aortic occlusive disease, large abdominal aortic aneurysm, and small abdominal aortic aneurysm samples. UBB was significantly enriched in proteolysis related pathways with a high degree in three groups. SPARCL1 was another gene shared by these groups and regulated by NFIA, which had a high degree in transcriptional regulatory network. ACTB, a significant upregulated gene in abdominal aortic aneurysm samples, could be regulated by CLIC4, which was significantly enriched in cell motions. ACLY and NFIB were separately identified in aortic occlusive disease and small abdominal aortic aneurysm samples, and separately enriched in lipid metabolism and negative regulation of cell proliferation. Conclusions The downregulated UBB, NFIA, and SPARCL1 might play key roles in both aortic occlusive disease and abdominal aortic aneurysm, while the upregulated ACTB might only involve in abdominal aortic aneurysm. ACLY and NFIB were specifically involved in aortic occlusive

  20. Incidence and progression of mild aortic regurgitation after Tirone David reimplantation valve-sparing aortic root replacement.

    Science.gov (United States)

    Stephens, Elizabeth H; Liang, David H; Kvitting, John-Peder Escobar; Kari, Fabian A; Fischbein, Michael P; Mitchell, R Scott; Miller, D Craig

    2014-01-01

    The study objective was to determine whether recurrent or residual mild aortic regurgitation, which occurs after valve-sparing aortic root replacement, progresses over time. Between 2003 and 2008, 154 patients underwent Tirone David-V valve-sparing aortic root replacement; 96 patients (62%) had both 1-year (median, 12 ± 4 months) and mid-term (62 ± 22 months) transthoracic echocardiograms available for analysis. Age of patients averaged 38 ± 13 years, 71% were male, 31% had a bicuspid aortic valve, 41% had Marfan syndrome, and 51% underwent aortic valve repair, predominantly cusp free margin shortening. Forty-one patients (43%) had mild aortic regurgitation on 1-year echocardiogram. In 85% of patients (n = 35), mild aortic regurgitation remained stable on the most recent echocardiogram (median, 57 ± 20 months); progression to moderate aortic regurgitation occurred in 5 patients (12%) at a median of 28 ± 18 months and remained stable thereafter; severe aortic regurgitation developed in 1 patient, eventually requiring reoperation. Five patients (5%) had moderate aortic regurgitation at 1 year, which did not progress subsequently. Two patients (2%) had more than moderate aortic regurgitation at 1 year, and both ultimately required reoperation. Although mild aortic regurgitation occurs frequently after valve-sparing aortic root replacement, it is unlikely to progress over the next 5 years and should not be interpreted as failure of the valve-preservation concept. Further, we suggest that mild aortic regurgitation should not be considered nonstructural valve dysfunction, as the 2008 valve reporting guidelines would indicate. We need 10- to 15-year follow-up to learn the long-term clinical consequences of mild aortic regurgitation early after valve-sparing aortic root replacement. Copyright © 2014 The American Association for Thoracic Surgery. Published by Mosby, Inc. All rights reserved.

  1. Combined Repair of Ascending Aortic Pseudoaneurysm and Abdominal Aortic Aneurysm in a Patient with Marfan Syndrome

    Science.gov (United States)

    Kokotsakis, John N.; Lioulias, Achilleas G.; Foroulis, Christophoros N.; Skouteli, Eleni Anna T.; Milonakis, Michael K.; Bastounis, Elias A.; Boulafendis, Dimitrios G.

    2003-01-01

    Pseudoaneurysms of the ascending aorta after the original inclusion/wrap technique of the Bentall procedure present a difficult surgical management problem and are associated with substantial morbidity and mortality. Patients with Marfan syndrome frequently develop aneurysms and dissections that involve multiple aortic segments. We present the case of a Marfan patient who successfully underwent repair of a giant ascending aortic pseudoaneurysm and concomitant repair of an abdominal aortic aneurysm. An aggressive surgical strategy followed by life-long cardiovascular monitoring is warranted in order to prolong the survival of these patients. (Tex Heart Inst J 2003;30:233–5) PMID:12959210

  2. New-Onset Atrial Fibrillation After Surgical Aortic Valve Replacement and Transcatheter Aortic Valve Implantation

    DEFF Research Database (Denmark)

    Jørgensen, Troels Højsgaard; Thygesen, Julie Bjerre; Thyregod, Hans Gustav

    2015-01-01

    Surgical aortic valve replacement (SAVR) and, more recently, transcatheter aortic valve implantation (TAVI) have been shown to be the only treatments that can improve the natural cause of severe aortic valve stenosis. However, after SAVR and TAVI, the incidence of new-onset atrial fibrillation...... (NOAF) is 31%-64% and 4%-32%, respectively. NOAF is independently associated with adverse events such as stroke, death, and increased length of hospital stay. Increasing the knowledge of predisposing factors, optimal postprocedural monitoring, and prophylactic antiarrhythmic and antithrombotic therapy...

  3. New-onset atrial fibrillation after surgical aortic valve replacement and transcatheter aortic valve implantation

    DEFF Research Database (Denmark)

    Jørgensen, Troels Højsgaard; Thygesen, Julie Bjerre; Thyregod, Hans Gustav

    2015-01-01

    Surgical aortic valve replacement (SAVR) and, more recently, transcatheter aortic valve implantation (TAVI) have been shown to be the only treatments that can improve the natural cause of severe aortic valve stenosis. However, after SAVR and TAVI, the incidence of new-onset atrial fibrillation...... (NOAF) is 31%-64% and 4%-32%, respectively. NOAF is independently associated with adverse events such as stroke, death, and increased length of hospital stay. Increasing the knowledge of predisposing factors, optimal postprocedural monitoring, and prophylactic antiarrhythmic and antithrombotic therapy...

  4. Refractory pulmonary edema secondary to severe aortic valvular stenosis - aortic valvuloplasty as bridge therapy to surgery

    International Nuclear Information System (INIS)

    Santiago, Salazar; Hanna, Franklin; Capasso, Aminta

    2009-01-01

    Aortic valve stenosis is a progressive disease; when it is severe and symptomatic has a bleak prognosis that affects adversely the patient survival. In these cases, the treatment of choice is valve replacement surgery that under certain circumstances can bear a huge risk that forces the physician to consider less aggressive management alternatives to solve the problem. The case of a 65 years old male with severe aortic valve stenosis is reported. He developed pulmonary edema refractory to medical treatment that was solved by aortic valvuloplasty as bridge therapy to surgery.

  5. Proposed new mechanism of traumatic aortic rupture

    International Nuclear Information System (INIS)

    Crass, J.R.; Cohen, A.M.; Motta, A.O.; Tomashefski, J.F.; Wiesen, E.

    1990-01-01

    The currently accepted mechanism to explain traumatic aortic rupture from rapid deceleration invokes a combination of traction, torsion, and hydrostatic forces. None of these forces individually is of adequate magnitude to result in aortic disruption. This paper proposes a theory, that aortic lacerations result from a pinch of the aorta between the spine and the anterior bony thorax during the chest compression caused by abrupt deceleration. Three sets of experiments were performed. Geometric analysis of CT images and compression of an articulated skeleton were performed to assess where the anterior and posterior osseous structures would contact if maximally compressed. Fresh dog aortas were pinched in a manner that would mimic the manubrium impacting the spine. Finally, attempts were made to tear an aorta via traction and torsion (whiplash)

  6. Global Strain in Severe Aortic Valve Stenosis

    DEFF Research Database (Denmark)

    Dahl, Jordi S; Videbæk, Lars; Poulsen, Mikael K

    2012-01-01

    Score, history with ischemic heart disease and ejection fraction. CONCLUSIONS: -In patients with symptomatic severe aortic stenosis undergoing AVR reduced GLS provides important prognostic information beyond standard risk factors. Clinical Trial Registration-URL: http://www.clinicaltrial.gov. Unique identifier......BACKGROUND: -Global longitudinal systolic strain (GLS) is often reduced in aortic stenosis despite normal ejection fraction. The importance of reduced preoperative GLS on long-term outcome after aortic valve replacement (AVR) is unknown. METHODS AND RESULTS: -A total of 125 patients with severe...... and mortality. In a stepwise cox model with forward selection GLS was the sole independent predictor HR=1.13 (95% confidence interval 1.02-1.25), p=0.04. Comparing the overall log likelihood χ(2) of the predictive power of the multivariable model containing GLS was statistically superior to models based on Euro...

  7. Flow measurement at the aortic root

    DEFF Research Database (Denmark)

    Bertelsen, Litten; Svendsen, Jesper Hastrup; Køber, Lars

    2016-01-01

    during CMR and aortic stenosis were excluded from the analyses. Stroke volumes were measured volumetrically (SVref) from steady-state free precision short axis images covering the entire left ventricle, excluding the papillary muscles and including the left ventricular outflow tract. Flow sequences......BACKGROUND: Cardiovascular magnetic resonance (CMR) is considered the gold standard of cardiac volumetric measurements. Flow in the aortic root is often measured at the sinotubular junction, even though placing the slice just above valve level may be more precise. It is unknown how much flow...... theoretically be equal to flow measurements, SVV and SVST were compared to SVref. RESULTS: Initially, 152 patients were included. 22 were excluded because of arrhythmias during scans and 9 were excluded for aortic stenosis. Accordingly, data from 121 patients were analysed and of these 63 had visually evident...

  8. Magnesium prevents phosphate-induced vascular calcification via TRPM7 and Pit-1 in an aortic tissue culture model.

    Science.gov (United States)

    Sonou, Tomohiro; Ohya, Masaki; Yashiro, Mitsuru; Masumoto, Asuka; Nakashima, Yuri; Ito, Teppei; Mima, Toru; Negi, Shigeo; Kimura-Suda, Hiromi; Shigematsu, Takashi

    2017-06-01

    Previous clinical and experimental studies have indicated that magnesium may prevent vascular calcification (VC), but mechanistic characterization has not been reported. This study investigated the influence of increasing magnesium concentrations on VC in a rat aortic tissue culture model. Aortic segments from male Sprague-Dawley rats were incubated in serum-supplemented high-phosphate medium for 10 days. The magnesium concentration in this medium was increased to demonstrate its role in preventing VC, which was assessed by imaging and spectroscopy. The mineral composition of the calcification was analyzed using Fourier transform infrared (FTIR) spectroscopic imaging, scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX) mapping. Magnesium supplementation of high-phosphate medium dose-dependently suppressed VC (quantified as aortic calcium content), and almost ablated it at 2.4 mm magnesium. The FTIR images and SEM-EDX maps indicated that the distribution of phosphate (as hydroxyapatite), phosphorus and Mg corresponded with calcium content in the aortic ring and VC. The inhibitory effect of magnesium supplementation on VC was partially reduced by 2-aminoethoxy-diphenylborate, an inhibitor of TRPM7. Furthermore, phosphate transporter-1 (Pit-1) protein expression was increased in tissues cultured in HP medium and was gradually-and dose dependently-decreased by magnesium. We conclude that a mechanism involving TRPM7 and Pit-1 underpins the magnesium-mediated reversal of high-phosphate-associated VC.

  9. Possible mechanisms involved in the vasorelaxant effect produced by clobenzorex in aortic segments of rats.

    Science.gov (United States)

    Lozano-Cuenca, J; González-Hernández, A; López-Canales, O A; Villagrana-Zesati, J R; Rodríguez-Choreão, J D; Morín-Zaragoza, R; Castillo-Henkel, E F; López-Canales, J S

    2017-08-07

    Clobenzorex is a metabolic precursor of amphetamine indicated for the treatment of obesity. Amphetamines have been involved with cardiovascular side effects such as hypertension and pulmonary arterial hypertension. The aim of the present study was to investigate whether the direct application of 10-9-10-5 M clobenzorex on isolated phenylephrine-precontracted rat aortic rings produces vascular effects, and if so, what mechanisms may be involved. Clobenzorex produced an immediate concentration-dependent vasorelaxant effect at the higher concentrations (10-7.5-10-5 M). The present outcome was not modified by 10-6 M atropine (an antagonist of muscarinic acetylcholine receptors), 3.1×10-7 M glibenclamide (an ATP-sensitive K+ channel blocker), 10-3 M 4-aminopyridine (4-AP; a voltage-activated K+ channel blocker), 10-5 M indomethacin (a prostaglandin synthesis inhibitor), 10-5 M clotrimazole (a cytochrome P450 inhibitor) or 10-5 M cycloheximide (a general protein synthesis inhibitor). Contrarily, the clobenzorex-induced vasorelaxation was significantly attenuated (Pclobenzorex on phenylephrine-precontracted rat aortic rings involved stimulation of the NO/cGMP/PKG/Ca2+-activated K+ channel pathway.

  10. JS-K has potent anti-angiogenic activity in vitro and inhibits tumour angiogenesis in a multiple myeloma model in vivo.

    Science.gov (United States)

    Kiziltepe, Tanyel; Anderson, Kenneth C; Kutok, Jeffery L; Jia, Lee; Boucher, Kenneth M; Saavedra, Joseph E; Keefer, Larry K; Shami, Paul J

    2010-01-01

    Glutathione S-transferases (GSTs) play an important role in multidrug resistance and are upregulated in multiple cancers. We have designed a prodrug class that releases nitric oxide on metabolism by GST. O(2)-(2,4-Dinitrophenyl) 1-[(4-ethoxycarbonyl)piperazin-1-yl]diazen-1-ium-1,2-diolate (JS-K, a member of this class) has potent antineoplastic activity. We studied the effect of JS-K on angiogenesis in human umbilical vein endothelial cells (HUVECs), OPM1 multiple myeloma cells, chick aortic rings and in mice. JS-K inhibited the proliferation of HUVECs with a 50% inhibitory concentration (IC50) of 0.432, 0.466 and 0.505 microm at 24, 48 and 72 h, respectively. In the cord formation assay, JS-K led to a decrease in the number of cord junctions and cord length with an IC50 of 0.637 and 0.696 microm, respectively. JS-K inhibited cell migration at 5 h using VEGF as a chemoattractant. Migration inhibition occurred with an IC50 of 0.493 microm. In the chick aortic ring assay using VEGF or FGF-2 for vessel growth stimulation, 0.5 microm JS-K completely inhibited vessel growth. JS-K inhibited tumour angiogenesis in vivo in NIH III mice implanted subcutaneously with OPM1 multiple myeloma cells. JS-K is a potent inhibitor of angiogenesis in vitro and tumour vessel growth in vivo. As such, it establishes a new class of antineoplastic agent that targets the malignant cells directly as well as their microenvironment.

  11. SOR-ring failure

    International Nuclear Information System (INIS)

    Kitamura, Hideo

    1981-01-01

    It was in the autumn of 1976 that the SOR-ring (synchrotron radiation storage ring) has commenced the regular operation. Since then, the period when the operation was interrupted due to the failures of SOR-ring itself is in total about 8 weeks. Failures and accidents have occurred most in the vacuum system. Those failure experiences are described on the vacuum, electromagnet, radio-frequency acceleration and beam transport systems with their interrupted periods. The eleven failures in the vacuum system have been reported, such as bellows breakage in a heating-evacuating period, leakage from the bellows of straight-through valves (made in U.S.A. and Japan), and leakage from the joint flange of the vacuum system. The longest interruption was 5 weeks due to the failure of a domestically manufactured straight-through valve. The failures of the electromagnet system involve the breakage in a cooling water system, short circuit of a winding in the Q magnet power transformer, blow of a fuse protecting the deflection magnet power source by the current less than the rating, and others. The failures of the RF acceleration system include the breakage of an output electronic tube the breakage of a cavity ceramic, RF voltage fluctuation due to the contact deterioration at a cavity electrode, and the failure of grid bias power source. It is necessary to select the highly reliable components for the vacuum system because the vacuum system failures require longer time for recovery, and very likely to induce secondary and tertiary failures. (Wakatsuki, Y.)

  12. A geometric reappraisal of proximal landing zones for thoracic endovascular aortic repair according to aortic arch types

    NARCIS (Netherlands)

    Marrocco-Trischitta, Massimiliano M.; de Beaufort, Hector W.; Secchi, Francesco; van Bakel, Theodorus M.; Ranucci, Marco; van Herwaarden, Joost A.; Moll, Frans L.; Trimarchi, Santi

    Objective: This study assessed whether the additional use of the aortic arch classification in type I, II, and III may complement Ishimaru's aortic arch map and provide valuable information on the geometry and suitability of proximal landing zones for thoracic endovascular aortic repair. Methods:

  13. Diagnostic imaging of acute aortic dissection

    International Nuclear Information System (INIS)

    Ohya, Tohru; Kumazaki, Tatsuo

    1991-01-01

    One hundred and nineteen patients with aortic dissection who underwent diagnostic imaging were reviewed and angiographic findings as well as those of CT were analysed. Thirty eight cases (43.1%) had non-contrast opacified false lumen, the type of which we call 'thrombosed type aortic dissection'. A comparative study of the thrombosed type with the patent type of false lumens was made particularly from the stand point of the characteristic diagnostic imagings (CT and angiography). At the same time, the pitfalls of these imagings in thrombosed type aortic dissection were studied. At the onset the average age of thrombosed type was 62.3 years old, while that of the patent type was 57.3. A statistical significance between the two groups was p<0.05. Thrombosed type in all cases was caused by atherosclerosis, whereas patent type was caused by the Marfan's syndrome in 11 cases. Other clinical findings, such as initial symptoms and blood pressure revealed no significant differences between the two groups. Pre-contrast CT in acute thrombosed type aortic dissection showed 'hyperdense crescent sign' in 89.4%. However, in 3 cases with thrombosed type in which the pre-contrast CT showed 'hyperdense crescent sign' contrast-enhanced CT detected no clear evidence of aortic dissection in the same site. This was due to obscurity induced by contrast medium. Angiographic findings of thrombosed type were classified into 3 groups: normal type, stenosed true lumen type and ulcer-like projection type. The incidence of normal type was estimated to be 48.4%, whereas stenosed true lumen type was 24.2% and ulcer-like projection was 27.7%. The present study concluded that thrombosed type is not rare in acute aortic dissection and contrast-enhanced CT as well as pre-contrast CT, is of great value in diagnosing thrombosed type. 'Hyperdense crescent sign' in pre-contrast CT is characteristic of intramural hematoma. (author)

  14. Aortic root surgery in Marfan syndrome.

    Science.gov (United States)

    Sheick-Yousif, Basheer; Sheinfield, Ami; Tager, Salis; Ghosh, Probal; Priesman, Sergey; Smolinsky, Aram K; Raanani, Ehud

    2008-03-01

    As the shortcomings of the Bentall operation and its variants in the Marfan syndrome have become apparent, the recent cusp-sparing techniques (remodeling or reimplantation) bear promise of better mid-term and long-term outcomes. To examine the results of aortic root surgery in patients with Marfan syndrome. During the period March 1994 to September 2007, 220 patients underwent aortic valve-sparing surgery; 20 were Marfan patients (group 1) who were compared with another 20 Marfan patients undergoing composite aortic root replacement (group 2). Fourteen patients had aortic dissection and 26 had thoracic aortic aneurysm. There were 31 males and 9 females with a mean age of 37.9 +/- 13.8 years. In group 1, reimplantation was used in 13 patients, remodeling in 4, and aortic valve repair with sinotubular junction replacement in 3. In group 2, a mechanical valve conduit was used. Mean logistic Euroscore was 12.27 +/- 14.6% for the whole group, five of whom were emergent cases Group 2 had more previous cardiac procedures compared to group 1 (9 vs. 2, P = 0.03) and shorter cross-clamp time (122 +/- 27.1 vs. 153.9 +/- 23.7 minutes, P = 0.0004). Overall mortality was 10%. Early mortality was 10% in group 2 and 5% in group 1 (NS). Mean follow-up time was 25 months for group 2 and 53 months for group 1. Three patients were reoperated; all had undergone the remodeling. Five year freedom from reoperation and death was 86% and 90% in group 2 and 70% and 95% in group 1 (P = 0.6, P = 0.6), respectively. Late survival of patients with Marfan syndrome was similar in both groups. Root reconstruction tends towards a higher incidence of late reoperations if the remodeling technique is used. We now prefer to use the reimplantation technique.

  15. Bentall Procedure Using Cryopreserved Valved Aortic Homografts

    Science.gov (United States)

    Christenson, Jan T.; Sierra, Jorge; Trindade, Pedro T.; Didier, Dominique; Kalangos, Afksendiyos

    2004-01-01

    The Bentall procedure is the standard operation for patients who have lesions of the ascending aorta associated with aortic valve disease. In many cases, however, mechanical prosthetic conduits are not suitable. There are few reports in the English-language medical literature concerning the mid- to long-term outcome of Bentall operations with cryopreserved homografts. Therefore, we reviewed our experience with this procedure and valved homografts. From January 1997 through December 2002, 21 patients underwent a Bentall operation with cryopreserved homografts at our institution. There were 14 males and 7 females; the mean age was 36 ± 21 years (range, 15–74 years). Eleven patients had undergone previous aortic valve surgery. All patients had aortic dilatation or aneurysms involving the ascending aorta. Indications for surgery included aortic valve stenosis or insufficiency, and aortic valve endocarditis (native valve or prosthetic). One patient had Takayasu's arteritis and 3 had Marfan syndrome. There was 1 hospital death (due to sepsis), but no other major postoperative complications. The mean hospital stay was 14 ± 7 days. Follow-up echocardiographic and computed tomographic scans were performed yearly. The mean follow-up was 34 months (6–72 months). Follow-up imaging revealed no calcifications or degenerative processes related to the homograft. Four patients had minimal valve regurgitation. Two patients died during follow-up. The 3-year actuarial survival rate was 85.7%. Our data suggest that the Bentall procedure with a valved homograft conduit is a safe procedure with excellent mid- to long-term results, comparable to results reported with aortic valve replacement with a homograft. PMID:15745290

  16. Anesthesia Approach in Endovascular Aortic Reconstruction

    Directory of Open Access Journals (Sweden)

    Ayşin Alagöl

    2013-03-01

    Full Text Available Introduction: We have analyzed our initial results of our anesthesia techniques in our new-onset endovascular aortic reconstruction cases.Patients and Methods: The perioperative data of 15 elective and emergent endovascular aortic reconstruction cases that were operated in 2010-2011 were collected in a database. The choice of anesthesia was made by the risk factors, surgical team’s preferences, type and location of the aortic pathology and by the predicted operation duration. The data of local and general anesthesia cases were compared.Results: Thirteen (86.7% cases were male and 2 (13.3% female. Eleven patients were in ASA Class III. The demographic parameters, ASA classifications, concurrent diseases were similar in both groups. Thirteen (86.7% cases had infrarenal abdominal aortic aneurysm and 2 (13.3% had Type III aortic dissection. The diastolic arterial pressures were lower in general anesthesia group in 20th and 40th minutes’ measurements just like the mean arterial pressure measurements at the 40th, 100th minutes and during the deployment of the graft. Postoperative mortality occurred in 3 (20.0% patients and they all had general anesthesia and they were operated on emergency basis. Postoperative morbidity occurred in four patients that had general anesthesia (acute renal failure, multi-organ failure and pneumonia. The other patient had atrial fibrillation on the 1st postoperative day and was converted to sinus rhythm with amiodarone infusion.Conclusion: Edovascular aortic reconstruction procedures can safely be performed with both general and local anesthesia less invasively compared to open surgery. General anesthesia may be preferred for the better hemodynamic control.

  17. Proton storage rings

    International Nuclear Information System (INIS)

    Rau, R.R.

    1978-04-01

    A discussion is given of proton storage ring beam dynamic characteristics. Topics considered include: (1) beam energy; (2) beam luminosity; (3) limits on beam current; (4) beam site; (5) crossing angle; (6) beam--beam interaction; (7) longitudinal instability; (8) effects of scattering processes; (9) beam production; and (10) high magnetic fields. Much of the discussion is related to the design parameters of ISABELLE, a 400 x 400 GeV proton---proton intersecting storage accelerator to be built at Brookhaven National Laboratory

  18. Ring-constrained Join

    DEFF Research Database (Denmark)

    Yiu, Man Lung; Karras, Panagiotis; Mamoulis, Nikos

    2008-01-01

    . This new operation has important applications in decision support, e.g., placing recycling stations at fair locations between restaurants and residential complexes. Clearly, RCJ is defined based on a geometric constraint but not on distances between points. Thus, our operation is fundamentally different......We introduce a novel spatial join operator, the ring-constrained join (RCJ). Given two sets P and Q of spatial points, the result of RCJ consists of pairs (p, q) (where p ε P, q ε Q) satisfying an intuitive geometric constraint: the smallest circle enclosing p and q contains no other points in P, Q...

  19. Femtoslicing in Storage Rings

    CERN Document Server

    Khan, Shaukat

    2005-01-01

    The generation of ultrashort synchrotron radiation pulses by laser-induced energy modulation of electrons and their subsequent transverse displacement, now dubbed "femtoslicing," was demonstrated at the Advanced Light Source in Berkeley. More recently, a femtoslicing user facility was commissioned at the BESSY storage ring in Berlin, and another project is in progress at the Swiss Light Source. The paper reviews the principle of femtoslicing, its merits and shortcomings, as well as the variations of its technical implementation. Various diagnostics techniques to detect successful laser-electron interaction are discussed and experimental results are presented.

  20. Hypotensive effect of aqueous extract of Averrhoa carambola L. (Oxalidaceae) in rats: an in vivo and in vitro approach.

    Science.gov (United States)

    Soncini, Roseli; Santiago, Michael B; Orlandi, Lidiane; Moraes, Gabriel O I; Peloso, André Luiz M; dos Santos, Marcelo H; Alves-da-Silva, Geraldo; Paffaro, Valdemar A; Bento, Antonio C; Giusti-Paiva, Alexandre

    2011-01-27

    Averrhoa carambola L. (Oxalidaceae) leaves are used in Brazilian traditional medicine to treat hypertension. This study was conducted to evaluate the hypotensive effect of the aqueous extract of Averrhoa carambola (AEAc) and its underlying mechanisms in the isolated rat aorta. The effect of AEAc on the mean arterial pressure (MAP) was determined in vivo in anesthetized rats. In vitro, thoracic aortic rings were isolated and suspended in organ baths, and the effects of AEAc were studied by means of isometric tension recording experiments. In HPLC analysis, the fingerprint chromatogram of AEAc was established. In normotensive rats, AEAc (12.5-50.0 mg/kg, i.v.) induced dose-dependent hypotension. In vitro, AEAc caused a depression in the E(max) response to phenylephrine without a change in sensibility. Also, in a depolarized Ca(2+)-free medium, AEAc inhibited CaCl(2)-induced contractions and caused a concentration-dependent rightward shift of the response curves, indicating that AEAc inhibited the contractile mechanisms involving extracellular Ca(2+) influx. These results demonstrate the hypotensive effects of AEAc, and these effects may, in part, be due to the inhibition of Ca(2+), which supports previous claims of its traditional use. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

  1. Viscosity of ring polymer melts

    KAUST Repository

    Pasquino, Rossana

    2013-10-15

    We have measured the linear rheology of critically purified ring polyisoprenes, polystyrenes, and polyethyleneoxides of different molar masses. The ratio of the zero-shear viscosities of linear polymer melts η0,linear to their ring counterparts η0,ring at isofrictional conditions is discussed as a function of the number of entanglements Z. In the unentangled regime η0,linear/η 0,ring is virtually constant, consistent with the earlier data, atomistic simulations, and the theoretical expectation η0,linear/ η0,ring = 2. In the entanglement regime, the Z-dependence of ring viscosity is much weaker than that of linear polymers, in qualitative agreement with predictions from scaling theory and simulations. The power-law extracted from the available experimental data in the rather limited range 1 < Z < 20, η0,linear/η0,ring ∼ Z 1.2±0.3, is weaker than the scaling prediction (η0,linear/η0,ring ∼ Z 1.6±0.3) and the simulations (η0,linear/ η0,ring ∼ Z2.0±0.3). Nevertheless, the present collection of state-of-the-art experimental data unambiguously demonstrates that rings exhibit a universal trend clearly departing from that of their linear counterparts, and hence it represents a major step toward resolving a 30-year-old problem. © 2013 American Chemical Society.

  2. Viscosity of ring polymer melts

    KAUST Repository

    Pasquino, Rossana; Vasilakopoulos, Thodoris C.; Jeong, Youncheol; Lee, Hyojoon; Rogers, Simon A.; Sakellariou, Georgios; Allgaier, Jü rgen B.; Takano, Atsushi; Brá s, Ana Rita E; Chang, Taihyun; Gooß en, Sebastian; Pyckhout-Hintzen, Wim; Wischnewski, Andreas; Hadjichristidis, Nikolaos; Richter, Dieter R.; Rubinstein, Michael H.; Vlassopoulos, Dimitris

    2013-01-01

    We have measured the linear rheology of critically purified ring polyisoprenes, polystyrenes, and polyethyleneoxides of different molar masses. The ratio of the zero-shear viscosities of linear polymer melts η0,linear to their ring counterparts η0,ring at isofrictional conditions is discussed as a function of the number of entanglements Z. In the unentangled regime η0,linear/η 0,ring is virtually constant, consistent with the earlier data, atomistic simulations, and the theoretical expectation η0,linear/ η0,ring = 2. In the entanglement regime, the Z-dependence of ring viscosity is much weaker than that of linear polymers, in qualitative agreement with predictions from scaling theory and simulations. The power-law extracted from the available experimental data in the rather limited range 1 < Z < 20, η0,linear/η0,ring ∼ Z 1.2±0.3, is weaker than the scaling prediction (η0,linear/η0,ring ∼ Z 1.6±0.3) and the simulations (η0,linear/ η0,ring ∼ Z2.0±0.3). Nevertheless, the present collection of state-of-the-art experimental data unambiguously demonstrates that rings exhibit a universal trend clearly departing from that of their linear counterparts, and hence it represents a major step toward resolving a 30-year-old problem. © 2013 American Chemical Society.

  3. Aortic valve replacement in octogenarians

    Directory of Open Access Journals (Sweden)

    Dark John H

    2007-07-01

    Full Text Available Abstract Background and Aims As our population ages and life expectancy increases the number of people aged over 80 and more referred for cardiac surgery is growing. This study sought to identify the outcome of aortic valve replacement (AVR in octogenarians. Methods 68 patients aged 80 years or more underwent AVR at the Freeman Hospital, between April 2001 and April 2004. A retrospective review of the notes and outcomes from the patients' GP and the NHS strategic tracking service was performed. 54% (37 underwent isolated AVR whilst 46% (31 underwent combined AVR and CABG. Results Follow up was 100% complete. The mean age was 83.1 ± s.d. 2.9 years, a mean gradient of 83 ± s.d. 31 mmHg and mean AVA of 0.56 cm2. The mean additive EuroSCORE was 8.6 ± s.d. 1.2, the logistic EuroSCORE mean 12.0 ± s.d. 5.9. In hospital 30 day mortality was 13 %. Survival was 80% at 1 year and 78% at 2 years. Median follow up was for 712 days. Stepwise logistic regression identified chronic obstructive airways disease as an independent predictor of mortality (p Conclusion Our study demonstrates that the operative mortality for AVR in the over eighties is good, whilst the mid to long term outcome is excellent There is a very low attrition rate with those undergoing the procedure living as long than their age matched population. This study confirms AVR is a safe, acceptable treatment for octogenarians with excellent mid term outcomes.

  4. Alpha - Skew Pi - Armendariz Rings

    Directory of Open Access Journals (Sweden)

    Areej M Abduldaim

    2018-03-01

    Full Text Available In this article we introduce a new concept called Alpha-skew Pi-Armendariz rings (Alpha - S Pi - ARas a generalization of the notion of Alpha-skew Armendariz rings.Another important goal behind studying this class of rings is to employ it in order to design a modern algorithm of an identification scheme according to the evolution of using modern algebra in the applications of the field of cryptography.We investigate general properties of this concept and give examples for illustration. Furthermore, this paperstudy the relationship between this concept and some previous notions related to Alpha-skew Armendariz rings. It clearly presents that every weak Alpha-skew Armendariz ring is Alpha-skew Pi-Armendariz (Alpha-S Pi-AR. Also, thisarticle showsthat the concepts of Alpha-skew Armendariz rings and Alpha-skew Pi- Armendariz rings are equivalent in case R is 2-primal and semiprime ring.Moreover, this paper proves for a semicommutative Alpha-compatible ringR that if R[x;Alpha] is nil-Armendariz, thenR is an Alpha-S Pi-AR. In addition, if R is an Alpha - S Pi -AR, 2-primal and semiprime ring, then N(R[x;Alpha]=N(R[x;Alpha]. Finally, we look forwardthat Alpha-skew Pi-Armendariz rings (Alpha-S Pi-ARbe more effect (due to their properties in the field of cryptography than Pi-Armendariz rings, weak Armendariz rings and others.For these properties and characterizations of the introduced concept Alpha-S Pi-AR, we aspire to design a novel algorithm of an identification scheme.

  5. Supravalvular aortic stenosis with sudden cardiac death

    Directory of Open Access Journals (Sweden)

    Pradeep Vaideeswar

    2015-01-01

    Full Text Available Sudden cardiac death (SCD most commonly results from previously undiagnosed congenital, acquired, or hereditary cardiac diseases. Congenital aortic valvular, subvalvular, and supravalvular disease with left ventricular outflow tract obstruction is an important preventable cause of sudden death. This report documents sudden death presumably due to acute myocardial ischemia in a young male with an undiagnosed supravalvular aortic stenosis (SVAS due to a rare association of isolation of coronary sinuses of Valsalva. Congenital supravalvular pulmonary stenosis and mitral valvular dysplasia were also present.

  6. Valve-sparing aortic root replacement†.

    Science.gov (United States)

    Koolbergen, David R; Manshanden, Johan S J; Bouma, Berto J; Blom, Nico A; Mulder, Barbara J M; de Mol, Bas A J M; Hazekamp, Mark G

    2015-02-01

    To evaluate our results of valve-sparing aortic root replacement and associated (multiple) valve repair. From September 2003 to September 2013, 97 patients had valve-sparing aortic root replacement procedures. Patient records and preoperative, postoperative and recent echocardiograms were reviewed. Median age was 40.3 (range: 13.4-68.6) years and 67 (69.1%) were male. Seven (7.2%) patients were younger than 18 years, the youngest being 13.4 years. Fifty-four (55.7%) had Marfan syndrome, 2 (2.1%) other fibrous tissue diseases, 15 (15.5%) bicuspid aortic valve and 3 (3.1%) had earlier Fallot repair. The reimplantation technique was used in all, with a straight vascular prosthesis in 11 (26-34 mm) and the Valsalva prosthesis in 86 (26-32 mm). Concomitant aortic valve repair was performed in 43 (44.3%), mitral valve repair in 10 (10.3%), tricuspid valve repair in 5 (5.2%) and aortic arch replacement in 3 (3.1%). Mean follow-up was 4.2 ± 2.4 years. Follow-up was complete in all. One 14-year old patient died 1.3 years post-surgery presumably of ventricular arrhythmia. One patient underwent reoperation for aneurysm of the proximal right coronary artery after 4.9 years and 4 patients required aortic valve replacement, 3 of which because of endocarditis after 0.1, 0.8 and 1.3 years and 1 because of cusp prolapse after 3.8 years. No thrombo-embolic complications occurred. Mortality, root reoperation and aortic regurgitation were absent in 88.0 ± 0.5% at 5-year follow-up. Results of valve-sparing root replacement are good, even in association with a high incidence of concomitant valve repair. Valve-sparing aortic root replacement can be performed at a very young age as long as an adult size prosthesis can be implanted. © The Author 2014. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

  7. Ruptured Aortic Aneurysm Presenting as a Stridor

    Directory of Open Access Journals (Sweden)

    Feng Lin

    2010-06-01

    Full Text Available Stridor is an abnormal, high-pitched, whining breathing sound caused by a blockage in the throat or larynx that is usually heard in children. We describe an unusual case of an 81-year-old man brought to our emergency department with sudden onset of dyspnea and shortness of breath. Stridor could be heard without a stethoscope. We found a huge mass over the left upper chest on chest radiography, suggesting an aortic aneurysm. We believed that these symptoms were caused by a huge thoracic aortic aneurysm with trachea/bronchi compression. Chest computed tomography confirmed the diagnosis.

  8. Infective endocarditis following transcatheter aortic valve replacement-

    DEFF Research Database (Denmark)

    Loh, Poay Huan; Bundgaard, Henning; S�ndergaard, Lars

    2013-01-01

    Transcatheter aortic valve replacement (TAVR) can improve the symptoms and prognosis of patients with severe aortic stenosis who, due to a high expected operative risk, would not have otherwise been treated surgically. If these patients develop prosthetic valve endocarditis, their presentations may...... be atypical causing a delay in the diagnosis and treatment. The management is also complicated by their comorbidities, and surgical treatment may not be feasible leading to a significant morbidity and mortality. We describe a case of an 85-year-old man with TAVI prosthetic valve endocarditis successfully...

  9. A bovine aortic arch in humans

    Directory of Open Access Journals (Sweden)

    María Elena Arnáiz-García

    2014-05-01

    Full Text Available We describe a curious congenital variation of human aortic arch (AA branching pattern termed the “bovine aortic arch”. Rather than arising directly from the AA as a separate branch as occurs in the most common AA branching pattern, the left common carotid artery moves to the right and merges from the brachiocephalic trunk. It is the normal AA branching pattern presented in a number of animals (canines, felines or Macaque monkeys but it has nothing to do with anatomy of AA in ruminant animals, including cattle and buffalo. That is why it is one of the most widely misnomers used in medical literature whose origin is nowadays unknown.

  10. Preventative Valve-Sparing Aortic Root Replacement and Pregnancy Outcome in Marfan Syndrome

    OpenAIRE

    Sokol, Vesna; Zlopaša, Gordan; Herman, Mislav; Planinić, Pavao; Micevska, Ana

    2012-01-01

    In Marfan syndrome, with dilatation of the aortic root secondary to an underlying connective tissue defect, pregnancy can cause hemodynamic stress leading to the development of an aortic aneurysm and even a fatal aortic dissection. In the presence of existing aortic root enlargement and a family history of aortic dissection, preventative elective surgery is suggested. Aortic root replacement with or without a valve-sparing procedure is superior to total aortic root replacement with ...

  11. A "blind" vascular ring in association with congenital cystic adenomatoid malformation: A case report.

    Science.gov (United States)

    Xia, Bo; Hong, Chun; Tang, Jing; Liu, Cuifen; Yu, Gang

    2017-12-01

    The occurrence of congenital cystic adenomatoid malformation (CCAM) and vascular ring (VR) is extremely rare. We present a case of left CCAM with VR consisting of a left aortic arch and right descending aorta with left tracheal compression causing atelectasis. A high-risk male neonate with the diagnosis of left CCAM was diagnosed at 20 weeks gestational age by antenatal ultrasound. Chest CT revealed multiple cysts in the left inferior lung. Cardiac CT showed VR consisting of a left aortic arch and right descending aorta with left tracheal compression causing atelectasis. left inferior lobectomy was performed. Cardiac CT showed VR consisting of a left aortic arch and right descending aorta with left tracheal compression causing atelectasis. Descending aorta transposition was performed. The patient recovered smoothly and remained asymptomatic during the 12-months of postoperative follow-up period. We report this rare case of CCAM with VR consisting of left aortic arch and right descending aorta with left tracheal compression causing atelectasis. From the findings of this report, early surgical treatment is recommended. Although the prognosis after surgery remained good, second surgery can be avoided if VR was detected early. Copyright © 2017 The Authors. Published by Wolters Kluwer Health, Inc. All rights reserved.

  12. Stimulation of aortic smooth muscle cell mitogenesis by serotonin

    International Nuclear Information System (INIS)

    Nemecek, G.M.; Coughlin, S.R.; Handley, D.A.; Moskowitz, M.A.

    1986-01-01

    Bovine aortic smooth muscle cells in vitro responded to 1 nM to 10 μM serotonin with increased incorporation of [ 3 H]thymidine into DNA. The mitogenic effect of serotonin was half-maximal at 80 nM and maximal above 1 μM. At a concentration of 1 μM, serotonin stimulated smooth muscle cell mitogenesis to the same extent as human platelet-derived growth factor (PDGF) at 12 ng/ml. Tryptamine was ≅ 1/10th as potent as serotonin as a mitogen for smooth muscle cells. Other indoles that are structurally related to serotonin (D- and L-tryptophan, 5-hydroxy-L-tryptophan, N-acetyl-5-hydroxytryptamine, melatonin, 5-hydroxyindoleacetic acid, and 5-hydroxytryptophol) and quipazine were inactive. The stimulatory effect of serotonin on smooth muscle cell DNA synthesis required prolonged (20-24 hr) exposure to the agonist and was attenuated in the presence of serotonin D receptor antagonists. When smooth muscle cells were incubated with submaximal concentrations of serotonin and PDGF, synergistic rather than additive mitogenic responses were observed. These data indicate that serotonin has a significant mitogenic effect on smooth muscle cells in vitro, which appears to be mediated by specific plasma membrane receptors

  13. NRL ion ring program

    International Nuclear Information System (INIS)

    Kapetanakos, C.A.; Golden, J.; Drobot, A.; Mahaffey, R.A.; Marsh, S.J.; Pasour, J.A.

    1977-01-01

    An experiment is under way to form a storng proton ring using the 200 ka, 1.2 MeV, 50 nsec hollow proton beam recently generated at NRL. The 5 m long magnetic field configuration consists of a magnetic cusp, a compressing magnetic field, a gate field and a magnetic mirror. The midplane value of the magnetic mirror is such that the major radius of the ring will be about 10 cm. The degree of field reversal that will be achieved with 5 x 10 16 protons per pulse from the existing beam depends upon the field reversal is possible with the 600 kA proton beam that would be generated from the low inductance coaxial triode coupled to the upgraded Gamble II generator. The propagation and trapping of an intense proton beam in the experimental magnetic field configuration is investigated numerically. The results show that the self magnetic has a very pronounced effect on the dynamics of the gyrating protons

  14. Flexible ring seal

    International Nuclear Information System (INIS)

    Abbes, Claude; Gournier, Andre; Rouaud, Christian; Villepoix, Raymond de.

    1976-01-01

    The invention concerns a flexible metal ring seal, able to ensure a perfect seal between two bearings due to the crushing and elastic deformation properties akin to similar properties in elastomers. Various designs of seal of this kind are already known, particularly a seal made of a core formed by a helical wire spring with close-wound turns and with high axial compression ratio, closed on itself and having the shape of an annulus. This wire ring is surrounded by at least one envelope having at rest the shape of a toroidal surface of which the generating circle does not close on itself. In a particular design mode, the seal in question can include, around the internal spring, two envelopes of which one in contact with the spring is composed of a low ductility elastic metal, such as mild steel or stainless steel and the other is, on the contrary, made of a malleable metal, such as copper or nickel. The first envelope evenly distributes the partial crushing of the spring, when the seal is tightened, on the second envelope which closely fits the two surfaces between which the seal operates. The stress-crushing curve characteristic of the seal comprises two separate parts, the first with a relatively sharp slope corresponds to the start of the seal compression phase, enabling at least some of these curves to reach the requisite seal threshold very quickly, then, beyond this, a second part, practically flat, where the stress is appreciably constant for a wide operating bracket [fr

  15. Magnetization of two coupled rings

    International Nuclear Information System (INIS)

    Avishai, Y; Luck, J M

    2009-01-01

    We investigate the persistent currents and magnetization of a mesoscopic system consisting of two clean metallic rings sharing a single contact point in a magnetic field. Many novel features with respect to the single-ring geometry are underlined, including the explicit dependence of wavefunctions on the Aharonov-Bohm fluxes, the complex pattern of two-fold and three-fold degeneracies, the key role of length and flux commensurability, and in the case of commensurate ring lengths the occurrence of idle levels which do not carry any current. Spin-orbit interactions, induced by the electric fields of charged wires threading the rings, give rise to a peculiar version of the Aharonov-Casher effect where, unlike for a single ring, spin is not conserved. Remarkably enough, this can only be realized when the Aharonov-Bohm fluxes in both rings are neither integer nor half-integer multiples of the flux quantum

  16. Hybrid aortic repair with antegrade supra-aortic and renovisceral debranching from ascending aorta.

    Science.gov (United States)

    Del Castro-Madrazo, José Antonio; Rivas-Domínguez, Margarita; Fernández-Prendes, Carlota; Zanabili Al-Sibbai, Amer; Llaneza-Coto, José Manuel; Alonso-Pérez, Manuel

    2017-05-01

    Aortic dissection is a life threatening condition. Hybrid repair has been described for the treatment of complex aortic pathology such as thoracoabdominal aortic aneurysms (TAAA) and type A and B dissections, although open and total endovascular repair are also possible. Open surgery is still associated with substantial perioperative morbi-mortality rates, thus less invasive techniques such as endovascular repair and hybrid procedures can achieve good results in centers with experience. We present the case of a patient with a chronic type B dissection and TAAA degeneration that was treated in a single stage hybrid procedure with antegrade supra-aortic and renovisceral debranching from the ascending aorta and TEVAR. At three-year follow up, the patient is free of intervention-related complications.

  17. Strategy to avoid patient-prosthesis mismatch: aortic root enlargement.

    Science.gov (United States)

    Srivastava, Dharmendra Kumar; Sanki, Prokash; Bhattacharya, Subhankar; Siddique, Javed Veqar

    2014-02-01

    The choice of a valve with an effective orifice area matching the body surface area and providing efficient hemodynamics is an important factor affecting mortality and morbidity in patients undergoing aortic valve replacement. Our preventative strategy was to implant a larger prosthetic valve by aortic root enlargement using the Nunez procedure in 17 patients between February 2010 and January 2011. The decision to enlarge the aortic root was taken when the 19-mm sizer could not be negotiated easily through the aortic root, or on the basis of body surface area of the patient or type of prosthesis available. Postoperative reductions in peak and mean pressure gradients across aortic valve of 12.8-16.5 and 10.2-12.6 mm Hg, respectively, were observed. Postoperative effective orifice areas of the aortic valves were 1.1-1.5 cm(2). By upsizing the aortic valve, we were able to eliminate patient-prosthesis mismatch in 5 patients, and reduce severe patient-prosthesis mismatch to moderate in 11. Aortic root enlargement is a safe procedure. Therefore, cardiac surgeons should not be reluctant to enlarge the aortic root with an autologous pericardial patch to permit implantation of an adequate size of aortic valve prosthesis, with minimal additional aortic crossclamp time and no added cost.

  18. Altered aortic and cremaster muscle prostaglandin synthesis in diabetic rats

    International Nuclear Information System (INIS)

    Myers, T.O.; Messina, E.J.; Rodrigues, A.M.; Gerritsen, M.E.

    1985-01-01

    Alterations in the synthesis and release of prostaglandins have been reported in humans and animal models of diabetes mellitus. In the present study synthesis and release of prostaglandins by thoracic aorta and cremaster muscle of rats with streptozotocin-induced diabetes of 8 wk duration was compared with age-matched controls. Prostaglandin synthesis was assessed by the measurement of immunoreactive prostaglandin E2 (PGE2) and 6-ketoprostaglandin F1 alpha (6-keto-PGF1 alpha) release and by quantifying metabolism of exogenous [1- 14 C]arachidonic acid by thoracic aortic rings and minced cremaster muscle. These studies indicate that diminished prostacyclin (PGI2) and/or PGE2 production is not a general feature of all diabetic vascular tissues, suggesting that large and small blood vessels may not be similarly affected by diabetes in regard to the metabolism of exogenous arachidonic acid and the synthesis and release of prostaglandins. Furthermore, the vascular changes often observed in conjunction with diabetes, i.e., alterations in vascular reactivity and microangiopathy in small blood vessels and atherosclerosis of large blood vessels may be related in some way to the segmental differences observed in prostaglandin synthesis

  19. Is there a prospect for hybrid aortic arch surgery?

    Science.gov (United States)

    Bashir, Mohamad; Harky, Amer; Bilal, Haris

    2018-05-16

    The surge of endovascular repair of aortic aneurysm in current modern aortic surgery practice has been the key for surgical management of elective cases of thoracic aortic aneurysms. This has paved way for the combined hybrid approach to be amongst the armamentarium for the management of aortic arch disease. The pivotal understanding of the aortic arch natural history coupled with device technology advancement allowed surgeons insight into delivery of hybrid surgery with acceptable morbidity and mortality results. This review article provides current insights into hybrid technique of aortic arch aneurysm repair and the evidences behind its applicability to arch surgery. It is aimed to highlight the challenges encountered for this innovative approach and correlate its challenges to those that are met by the conventional open aortic arch repair.

  20. Aortic valve ochronosis: a rare manifestation of alkaptonuria.

    Science.gov (United States)

    Steger, Christina Maria

    2011-07-28

    Alkaptonuric ochronosis is a heritable disorder of tyrosine metabolism, with various systemic abnormalities related to pigment deposition and degeneration of collagen and other tissues, including the heart and aorta. A 65-year-old woman with alkaptonuric ochronosis and a history of four joint replacements required aortic valve replacement for severe aortic stenosis. Operative findings included ochronosis of a partly calcified aortic valve and the aortic intima. The aortic valve was removed at surgery and histologically investigated. Light microscopic examination of the aortic valve revealed intracellular and extracellular deposits of ochronotic pigment and a chronic inflammatory infiltrate. Beside the case representation, the disease history, aetiology, pathogenesis, clinical presentation and treatment of aortic valve ochronosis are reviewed.

  1. Vaginal health in contraceptive vaginal ring users - A review.

    Science.gov (United States)

    Lete, Iñaki; Cuesta, María C; Marín, Juan M; Guerra, Sandra

    2013-08-01

    To provide an overview of the available data from clinical studies of vaginal conditions in women who use a vaginal ring as a contraceptive. A systematic review of the literature. Millions of women have already used the ethylene vinyl acetate vaginal ring that releases ethinylestradiol and etonogestrel for contraception. Because of its small size, more than four out of five women using the ring report that they do not feel it, even during sexual intercourse. No colposcopic or cytological changes have been observed in users, although approximately 10% have increased vaginal discharge. While in vitro studies have shown adhesion of Candida yeasts to the vaginal ring surface, clinical studies have not demonstrated a greater incidence of Candida infections compared to users of equivalent oral contraceptives. Some clinical studies suggest a lower incidence of bacterial vaginosis. No interaction exists between concomitant use of the vaginal ring and other drugs or products for vaginal use. The use of a contraceptive vaginal ring does not alter the vaginal ecosystem and therefore does not substantially affect vaginal health.

  2. New predictor of aortic enlargement in uncomplicated type B aortic dissection based on elliptic Fourier analysis.

    Science.gov (United States)

    Sato, Hiroshi; Ito, Toshiro; Kuroda, Yosuke; Uchiyama, Hiroki; Watanabe, Toshitaka; Yasuda, Naomi; Nakazawa, Junji; Harada, Ryo; Kawaharada, Nobuyoshi

    2017-12-01

    This study aimed to re-examine the conventional predictive factors for dissected aortic enlargement, such as the aortic and false lumen diameter and to consider whether the morphological elements of the dissected aorta could be predictors by quantifying the 'shape' of the true lumen based on elliptic Fourier analysis. A total of 80 patients with uncomplicated type B aortic dissection were included. The patients were divided into 'Enlargement group' and 'No Change group.' Between the 2 groups, the mean systolic blood pressure during follow-up, aortic and false lumen maximum diameters, and analysed morphological data were compared using each statistical method. The maximum aortic and false lumen diameters were significantly larger in the Enlargement group than in the No Change group (39.3 vs 35.9 mm; P = 0.0058) (23.5 vs 18.2 mm; P = 0.000095). The principal component 1, which is the data calculated by elliptic Fourier analysis, was significantly lower in the Enlargement group than in the No Change group (0.020 vs - 0.072; P = 0.000049). The mean systolic blood pressure ≥130 mmHg, aortic diameter, false lumen diameter and principal component 1 were included in the Cox proportional hazard model as covariates to determine the significant predictive variable. Principal component 1 demonstrated the only significance with aortic enlargement on multivariate analysis (odds ratio = 0.32; P = 0.048). The analysed and calculated morphological data of the shape of the true lumen can be more effective predictive factors of aortic enlargement of type B dissection than the conventional factors. © The Author 2017. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

  3. Association of aortic valve calcification severity with the degree of aortic regurgitation after transcatheter aortic valve implantation.

    Science.gov (United States)

    Koos, Ralf; Mahnken, Andreas Horst; Dohmen, Guido; Brehmer, Kathrin; Günther, Rolf W; Autschbach, Rüdiger; Marx, Nikolaus; Hoffmann, Rainer

    2011-07-15

    This study sought to examine a possible relationship between the severity of aortic valve calcification (AVC), the distribution of AVC and the degree of aortic valve regurgitation (AR) after transcatheter aortic valve implantation (TAVI) for severe aortic stenosis (AS). 57 patients (22 men, 81 ± 5 years) with symptomatic AS and with a logistic EuroSCORE of 24 ± 12 were included. 38 patients (67%) received a third (18F)-generation CoreValve® aortic valve prosthesis, in 19 patients (33%) an Edwards SAPIEN™ prosthesis was implanted. Prior to TAVI dual-source computed tomography for assessment of AVC was performed. To determine the distribution of AVC the percentage of the calcium load of the most severely calcified cusp was calculated. After TAVI the degree of AR was determined by angiography and echocardiography. The severity of AR after TAVI was related to the severity and distribution of AVC. There was no association between the distribution of AVC and the degree of paravalvular AR after TAVI as assessed by angiography (r = -0.02, p = 0.88). Agatston AVC scores were significantly higher in patients with AR grade ≥ 3 (5055 ± 1753, n = 3) than in patients with AR grade AVC scores > 3000 were associated with a relevant paravalvular AR and showed a trend for increased need for second manoeuvres. There was a significant correlation between the severity of AVC and the degree of AR after AVR (r = 0.50, p AVC have an increased risk for a relevant AR after TAVI as well as a trend for increased need for additional procedures. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

  4. Fate of remnant sinuses of Valsalva in patients with bicuspid and trileaflet valves undergoing aortic valve, ascending aorta, and aortic arch replacement.

    Science.gov (United States)

    Milewski, Rita Karianna; Habertheuer, Andreas; Bavaria, Joseph E; Siki, Mary; Szeto, Wilson Y; Krause, Eric; Korutla, Varun; Desai, Nimesh D; Vallabhajosyula, Prashanth

    2017-08-01

    In patients presenting with aortic valvulopathy with concomitant ascending aortic aneurysm, surgical management of the sinus of Valsalva segment remains undefined, especially for moderately dilated aortic roots. In patients with this pathology undergoing aortic valve replacement with supracoronary ascending aorta replacement, we assessed the fate of the remnant preserved sinus of Valsalva segment stratified by aortic valve morphology and pathology. From 2002 to 2015, 428 patients underwent elective aortic valve replacement with supracoronary ascending aorta replacement. Patients were stratified on the basis of valvular morphology (bicuspid aortic valve [n = 254] and tricuspid aortic valve [n = 174]), valvular pathology (bicuspid aortic valve with aortic stenosis [n = 178], bicuspid aortic valve with aortic insufficiency [n = 76], tricuspid aortic valve with aortic stenosis [n = 61], tricuspid aortic valve with aortic insufficiency [n = 113]), and preoperative sinus of Valsalva dimensions (45 mm). Kaplan-Meier analysis revealed no significant difference in freedom from reoperation in tricuspid aortic valve versus bicuspid aortic valve (P = .576). Multivariable Cox regression model performed with sinus of Valsalva dimensions at baseline and follow-up as time-varying covariates did not adversely affect survival. A repeated-measure, mixed-effects model constructed to assess longitudinal sinus of Valsalva trends revealed that the retained sinus of Valsalva dimensions remain stable over long-term follow-up (discharge to ≥10 years), irrespective of valvular morphology/pathology (bicuspid aortic valve with aortic insufficiency, tricuspid aortic valve with aortic insufficiency, tricuspid aortic valve with aortic stenosis) and preoperative sinus of Valsalva groups (45 mm). In patients with nonaneurysmal sinuses of Valsalva undergoing aortic valve replacement with supracoronary ascending aorta replacement, the sinus segment can be preserved irrespective of

  5. Split ring containment attachment device

    International Nuclear Information System (INIS)

    Sammel, A.G.

    1996-01-01

    A containment attachment device is described for operatively connecting a glovebag to plastic sheeting covering hazardous material. The device includes an inner split ring member connected on one end to a middle ring member wherein the free end of the split ring member is inserted through a slit in the plastic sheeting to captively engage a generally circular portion of the plastic sheeting. A collar potion having an outer ring portion is provided with fastening means for securing the device together wherein the glovebag is operatively connected to the collar portion. 5 figs

  6. Radar imaging of Saturn's rings

    Science.gov (United States)

    Nicholson, Philip D.; French, Richard G.; Campbell, Donald B.; Margot, Jean-Luc; Nolan, Michael C.; Black, Gregory J.; Salo, Heikki J.

    2005-09-01

    We present delay-Doppler images of Saturn's rings based on radar observations made at Arecibo Observatory between 1999 and 2003, at a wavelength of 12.6 cm and at ring opening angles of 20.1°⩽|B|⩽26.7°. The average radar cross-section of the A ring is ˜77% relative to that of the B ring, while a stringent upper limit of 3% is placed on the cross-section of the C ring and 9% on that of the Cassini Division. These results are consistent with those obtained by Ostro et al. [1982, Icarus 49, 367-381] from radar observations at |B|=21.4°, but provide higher resolution maps of the rings' reflectivity profile. The average cross-section of the A and B rings, normalized by their projected unblocked area, is found to have decreased from 1.25±0.31 to 0.74±0.19 as the rings have opened up, while the circular polarization ratio has increased from 0.64±0.06 to 0.77±0.06. The steep decrease in cross-section is at variance with previous radar measurements [Ostro et al., 1980, Icarus 41, 381-388], and neither this nor the polarization variations are easily understood within the framework of either classical, many-particle-thick or monolayer ring models. One possible explanation involves vertical size segregation in the rings, whereby observations at larger elevation angles which see deeper into the rings preferentially see the larger particles concentrated near the rings' mid-plane. These larger particles may be less reflective and/or rougher and thus more depolarizing than the smaller ones. Images from all four years show a strong m=2 azimuthal asymmetry in the reflectivity of the A ring, with an amplitude of ±20% and minima at longitudes of 67±4° and 247±4° from the sub-Earth point. We attribute the asymmetry to the presence of gravitational wakes in the A ring as invoked by Colombo et al. [1976, Nature 264, 344-345] to explain the similar asymmetry long seen at optical wavelengths. A simple radiative transfer model suggests that the enhancement of the azimuthal

  7. Magnetic ring for stripping enhancement

    International Nuclear Information System (INIS)

    Selph, F.

    1992-10-01

    A ring designed to recycle ions through a stripping medium offers the possibility for increasing output of the desired charge state by up to 4x. This could be a very important component of a Radioactive Nuclear Beam Facility. In order for such a ring to work effectively it must satisfy certain design conditions. These include achromaticity at the stripper, a dispersed region for an extraction magnet, and a number of first and higher order optics constraints which are necessary to insure that the beam emittance is not degraded unduly by the ring. An example is given of a candidate design of a stripping ring

  8. Saturn's Rings Edge-on

    Science.gov (United States)

    1995-01-01

    In one of nature's most dramatic examples of 'now-you see-them, now-you-don't', NASA's Hubble Space Telescope captured Saturn on May 22, 1995 as the planet's magnificent ring system turned edge-on. This ring-plane crossing occurs approximately every 15 years when the Earth passes through Saturn's ring plane.For comparison, the top picture was taken by Hubble on December 1, 1994 and shows the rings in a more familiar configuration for Earth observers.The bottom picture was taken shortly before the ring plane crossing. The rings do not disappear completely because the edge of the rings reflects sunlight. The dark band across the middle of Saturn is the shadow of the rings cast on the planet (the Sun is almost 3 degrees above the ring plane.) The bright stripe directly above the ring shadow is caused by sunlight reflected off the rings onto Saturn's atmosphere. Two of Saturn's icy moons are visible as tiny starlike objects in or near the ring plane. They are, from left to right, Tethys (slightly above the ring plane) and Dione.This observation will be used to determine the time of ring-plane crossing and the thickness of the main rings and to search for as yet undiscovered satellites. Knowledge of the exact time of ring-plane crossing will lead to an improved determination of the rate at which Saturn 'wobbles' about its axis (polar precession).Both pictures were taken with Hubble's Wide Field Planetary Camera 2. The top image was taken in visible light. Saturn's disk appears different in the bottom image because a narrowband filter (which only lets through light that is not absorbed by methane gas in Saturn's atmosphere) was used to reduce the bright glare of the planet. Though Saturn is approximately 900 million miles away, Hubble can see details as small as 450 miles across.The Wide Field/Planetary Camera 2 was developed by the Jet Propulsion Laboratory and managed by the Goddard Spaced Flight Center for NASA's Office of Space Science.This image and other images and

  9. Acceleration of magnetized plasma rings

    International Nuclear Information System (INIS)

    Hartman, D.; Eddleman, J.; Hammer, J.H.

    1982-01-01

    One scheme is considered, acceleration of a ring between coaxial electrodes by a B/sub theta/ field as in a coaxial rail-gun. If the electrodes are conical, a ring accelerated towards the apex of the cone undergoes self-similar compression (focussing) during acceleration. Because the allowable acceleration force F/sub a/ = kappa U/sub m//R (kappa - 2 , the accelerating distance for conical electrodes is considerably shortened over that required for coaxial electrodes. In either case however, since the accelerating flux can expand as the ring moves, most of the accelerating field energy can be converted into kinetic energy of the ring leading to high efficiency

  10. Ground Movement in SSRL Ring

    International Nuclear Information System (INIS)

    Sunikumar, Nikita

    2011-01-01

    Users of the Stanford Synchrotron Radiation Lightsource (SSRL) are being affected by diurnal motion of the synchrotron's storage ring, which undergoes structural changes due to outdoor temperature fluctuations. In order to minimize the effects of diurnal temperature fluctuations, especially on the vertical motion of the ring floor, scientists at SSRL tried three approaches: painting the storage ring white, covering the asphalt in the middle of the ring with highly reflective Mylar and installing Mylar on a portion of the ring roof and walls. Vertical motion in the storage ring is measured by a Hydrostatic Leveling System (HLS), which calculates the relative height of water in a pipe that extends around the ring. The 24-hr amplitude of the floor motion was determined using spectral analysis of HLS data, and the ratio of this amplitude before and after each experiment was used to quantitatively determine the efficacy of each approach. The results of this analysis showed that the Mylar did not have any significant effect on floor motion, although the whitewash project did yield a reduction in overall HLS variation of 15 percent. However, further analysis showed that the reduction can largely be attributed to a few local changes rather than an overall reduction in floor motion around the ring. Future work will consist of identifying and selectively insulating these local regions in order to find the driving force behind diurnal floor motion in the storage ring.

  11. ring og refleksion

    DEFF Research Database (Denmark)

    Wahlgren, B.; Rattleff, Pernille; Høyrup, S.

    State of the art inden for forskning om læring på arbejdspladsen samt gennemgang af læringsteori og refleksionsbegrebet hos Dewey, Dreyfus, Schön, Argyris, Kolb, Jarvis, Mezirow og Brookfield. Afsluttes med diskussion af syntetiseret model for læring på arbejdspladsen.......State of the art inden for forskning om læring på arbejdspladsen samt gennemgang af læringsteori og refleksionsbegrebet hos Dewey, Dreyfus, Schön, Argyris, Kolb, Jarvis, Mezirow og Brookfield. Afsluttes med diskussion af syntetiseret model for læring på arbejdspladsen....

  12. Aorto-right atrial fistula after ascending aortic replacement or aortic value replacement

    International Nuclear Information System (INIS)

    Zhi Aihua; Dai Ruping; Jiang Shiliang; Lu Bin

    2012-01-01

    Objective: To evaluate the CT features of aorto-right atrial fistula after aortic valve replacement (AVR) or ascending aortic replacement. Methods: Eighty-seven patients with aortic-right atrial fistula underwent CT after operation. The CT features were retrospectively analyzed. Fistula was measured according to maximum width of the shunt. Results: Aorto-right atrial fistula was detected in 87 patients after aortic valve replacement or ascending aortic replacement by CT scan. Among them, 25 patients were diagnosed as mild aorto-right atrial fistula, 47 patients as moderate, and 15 patients as severe. Thirty-seven patients underwent follow-up CT.Among them, 10 patients with mild to moderate aorto-right atrial fistula were considered to have complete regression, 8 patients with mild aorto-right atrial fistula considered to have incomplete regression, 14 patients with mild to moderate aorto-right atrial fistula considered to have stable condition, and 5 patients with moderate aorto-right atrial fistula considered to have progression at the 3-month follow-up. Conclusion: CT is a useful tool for defining aorto-right atrial fistula after AVR or ascending aortic replacement and for evaluating it in follow-up. (authors)

  13. Abdominal aortic aneurysm development in men following a "normal" aortic ultrasound scan.

    Science.gov (United States)

    Hafez, H; Druce, P S; Ashton, H A

    2008-11-01

    To determine predictors related to abdominal aortic aneurysm (AAA) development following a "normal" aortic ultrasound scan. Over a 23-year period, 22 961 men participated in an AAA screening programme. Maximum aortic diameter of less than 30 mm was deemed "normal". 4308 of these "normal" individuals were later re-scanned at intervals for research purposes. AAA prevalence was 4.4% at initial scanning. In those with a normal scan, 46 patients subsequently presented with AAAs incidentally detected and 120 (2.8%) had AAAs identified as part of the ongoing surveillance. The median initial aortic size of these 166 men was 25 mm (range 15-29 mm). Over the follow-up period, there have been 24 (14%) AAA-related deaths, 24 patients underwent successful AAA surgery and 36 died of unrelated causes. In those with an initial aortic diameter of <25 mm who later developed an AAA, the odds ratio for AAA-related mortality was 2 (95% CI 1-4.1, p=0.03, x(2)). AAAs can develop following an initial "normal" scan and men with an aortic diameters of 25-29 mm appear to be at greater risk. Surveillance for this sub-group may further reduce the incidence of undiagnosed AAA and AAA-related mortality.

  14. Analysis of aortic root surgery with composite mechanical aortic valve conduit and valve-sparing reconstruction.

    Science.gov (United States)

    Dias, Ricardo Ribeiro; Mejia, Omar Asdrubal Vilca; Fiorelli, Alfredo Inácio; Pomerantzeff, Pablo Maria Alberto; Dias, Altamiro Ribeiro; Mady, Charles; Stolf, Noedir Antonio Groppo

    2010-01-01

    Comparative analysis of early and late results of aortic root reconstruction with aortic valve sparing operations and the composite mechanical valve conduit replacement. From November 2002 to September 2009, 164 consecutive patients with mean age 54 ± 15 years, 115 male, underwent the aortic root reconstruction (125 mechanical valve conduit replacements and 39 valve sparing operations). Sixteen percent of patients had Marfan syndrome and 4.3% had bicuspid aortic valve. One hundred and forty-four patients (88%) were followed for a mean period of 41.1 ± 20.8 months. The hospital mortality was 4.9%, 5.6% in operations with valved conduits and 2.6% in the valve sparing procedures (P valve sparing operations, respectively (95% CI = 70% - 95%, P = 0.001), (95% CI = 82% - 95% P = 0.03) and (95% CI = 81% - 95%, P = 0.03). Multivariate analysis showed that creatinine greater than 1.4 mg/dl, Cabrol operation and renal dialysis were predictors of mortality, respectively, with occurrence chance of 6 (95% CI = 1.8 - 19.5, P = 0.003), 12 (95% CI = 3 - 49.7, P = 0.0004) and 16 (95% CI = 3.6 - 71.3, P = 0.0002). The aortic root reconstruction has a low early and late mortality, high survival free of complications and low need for reoperation. During the late follow-up, valve sparing aortic root reconstructions presented fewer incidences of bleeding, thromboembolic events and endocarditis.

  15. Extended aortic repair using frozen elephant trunk technique for Marfan syndrome with acute aortic dissection.

    Science.gov (United States)

    Uchida, Naomichi; Katayama, Akira; Kuraoka, Masatsugu; Katayama, Keijiro; Takahashi, Shinya; Takasaki, Taiichi; Sueda, Taijiro

    2013-01-01

    The aim of this study was to analyze midterm results of frozen elephant trunk technique for Marfan syndrome with acute aortic dissection. Between February 1999 and August 2011 we performed arch replacement uisng frozen elephant trunk technique for acute aortic dissection in 8 patients with Marfan syndrome containing two complicated type B dissections and six type A dissections.Five patients compromised annulo-aortic ectasia who performed Bentall operation. No patients died in the initial operation. Fate of false lumen on the stent graft border was expressed by CT scan follow-up that were patent in 0, thrombosis in 5 and absorption in 3 patients. One patient who had new aortic dissection 8 years after initial surgery required the Crawford V operation. Ten-years-survival rate was 100% and ten years-event free rate was 67%. Frozen elephant trunk technique was feasible for Marfan syndrome with acute aortic dissection and might become alternative prophylactic treatment to the downstream aorta for acute aortic dissection.

  16. Ultrasonic delineation of aortic microstructure: The relative contribution of elastin and collagen to aortic elasticity

    Science.gov (United States)

    Marsh, Jon N.; Takiuchi, Shin; Lin, Shiow Jiuan; Lanza, Gregory M.; Wickline, Samuel A.

    2004-05-01

    Aortic elasticity is an important factor in hemodynamic health, and compromised aortic compliance affects not only arterial dynamics but also myocardial function. A variety of pathologic processes (e.g., diabetes, Marfan's syndrome, hypertension) can affect aortic elasticity by altering the microstructure and composition of the elastin and collagen fiber networks within the tunica media. Ultrasound tissue characterization techniques can be used to obtain direct measurements of the stiffness coefficients of aorta by measurement of the speed of sound in specific directions. In this study we sought to define the contributions of elastin and collagen to the mechanical properties of aortic media by measuring the magnitude and directional dependence of the speed of sound before and after selective isolation of either the collagen or elastin fiber matrix. Formalin-fixed porcine aortas were sectioned for insonification in the circumferential, longitudinal, or radial direction and examined using high-frequency (50 MHz) ultrasound microscopy. Isolation of the collagen or elastin fiber matrices was accomplished through treatment with NaOH or formic acid, respectively. The results suggest that elastin is the primary contributor to aortic medial stiffness in the unloaded state, and that there is relatively little anisotropy in the speed of sound or stiffness in the aortic wall.

  17. Vitamins and abdominal aortic aneurysm.

    Science.gov (United States)

    Takagi, Hisato; Umemoto, Takuya

    2017-02-01

    To summarize the association of vitamins (B6, B12, C, D, and E) and abdominal aortic aneurysm (AAA), we reviewed clinical studies with a comprehensive literature research and meta-analytic estimates. To identify all clinical studies evaluating the association of vitamins B6/B12/C/D/E and AAA, databases including MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials were searched through April 2015, using Web-based search engines (PubMed and OVID). For each case-control study, data regarding vitamin levels in both the AAA and control groups were used to generate standardized mean differences (SMDs) and 95% confidence intervals (CIs). Pooled analyses of the 4 case-control studies demonstrated significantly lower circulating vitamin B6 levels (SMD, -0.33; 95% CI, -0.55 to -0.11; P=0.003) but non-significantly lower vitamin B12 levels (SMD, -0.42; 95% CI, -1.09 to 0.25; P=0.22) in patients with AAA than subjects without AAA. Pooled analyses of the 2 case-control studies demonstrated significantly lower levels of circulating vitamins C (SMD, -0.71; 95% CI, -1.23 to -0.19; P=0.007) and E (SMD, -1.76; 95% CI, -2.93 to 0.60; P=0.003) in patients with AAA than subjects without AAA. Another pooled analysis of the 3 case-control studies demonstrated significantly lower circulating vitamin D (25-hydroxyvitamin D) levels (SMD, -0.25; 95% CI, -0.50 to -0.01; P=0.04) in patients with AAA than subjects without AAA. In a double-blind controlled trial, 4.0-year treatment with a high-dose folic acid and vitamin B6/B12 multivitamin in kidney transplant recipients did not reduce a rate of AAA repair despite significant reduction in homocysteine level. In another randomized, double-blind, placebo-controlled trial, 5.8-year supplementation with α-tocopherol (vitamin E) had no preventive effect on large AAA among male smokers. In clinical setting, although low circulating vitamins B6/C/D/E (not B12) levels are associated with AAA presence, vitamins B6/B12/E

  18. Mechanical Aortic Valve Replacement in Octogenarian

    Directory of Open Access Journals (Sweden)

    Irfan Tasoglu

    2013-10-01

    Full Text Available Aim: This study analyzes the long-term outcomes of mechanical aortic valve replacement in octogenarian patients. Material and Method: A retrospective review was performed on 23 octogenarian patients who underwent mechanical aortic valve replacement. Hospital mortality, postoperative intensive care unit stay, hospital stay and long-term results was examined. Estimates of the cumulative event mortality rate were calculated by the Kaplan-Meier method. Results: The mean age of all patients was 82.9±2.3 years and most were men (65.22%. The median ejection fraction was 45%. 73.91% of patients were in New York Heart Association class III-IV. Thirteen patients (56.52% in this study underwent combined procedure, the remaining 10 (43.48% patients underwent isolated aortic valve replacement. The most common valve size was 23 mm. The mean intensive care unit stay was 1.76±1.14 days. The mean hospital stay was 9.33±5.06 days. No complications were observed in 56.52% patients during their hospital stay. The overall hospital mortality was 8.7%. Follow-up was completed for all 23 patients. Median follow-up time was 33 months (1-108 months. Actuarial survival among discharged from hospital was 59% at 5 years. Discussion: Mechanical aortic valve replacement is a safe procedure in octogenarian patients and can be performed safely even in combined procedure.

  19. Natural history of abdominal aortic aneurysm

    DEFF Research Database (Denmark)

    Perko, M J; Schroeder, T V; Olsen, P S

    1993-01-01

    During a 10-year period in which 735 patients presented with abdominal aortic aneurysms to our clinic, 63 were not offered operative treatment. The primary reason for choosing conservative treatment was concomitant diseases that increased the risk of operation. After 2 years of followup, half...

  20. Autopsy after transcatheter aortic valve implantation

    NARCIS (Netherlands)

    van Kesteren, F.; Wiegerinck, E. M. A.; Rizzo, S.; Baan, J.; Planken, R. N.; von der Thüsen, J. H.; Niessen, H. W. M.; van Oosterhout, M. F. M.; Pucci, A.; Thiene, G.; Basso, C.; Sheppard, M. N.; Wassilew, K.; van der Wal, A. C.

    2017-01-01

    Autopsy after transcatheter aortic valve implantation (TAVI) is a new field of interest in cardiovascular pathology. To identify the cause of death, it is important to be familiar with specific findings related to the time interval between the procedure and death. We aimed to provide an overview of

  1. Severe aortic valve stenosis and nosebleed

    NARCIS (Netherlands)

    Schoedel, Johannes; Obergfell, Achim; Maass, Alexander H.; Schodel, Johannes

    2007-01-01

    Aortic valve stenosis is known to be associated with loss of high molecular von Willebrand multimers. This can lead to gastrointestinal bleeding in patients with gastrointestinal angiodysplasia, the Heyde syndrome. Here we present a case of anaemia and severe epistaxis associated with acquired von

  2. [Albert Einstein and his abdominal aortic aneurysm].

    Science.gov (United States)

    Cervantes Castro, Jorge

    2011-01-01

    The interesting case of Albert Einstein's abdominal aortic aneurysm is presented. He was operated on at age 69 and, finding that the large aneurysm could not be removed, the surgeon elected to wrap it with cellophane to prevent its growth. However, seven years later the aneurysm ruptured and caused the death of the famous scientist.

  3. Fatal Saccharomyces Cerevisiae Aortic Graft Infection

    Science.gov (United States)

    Meyer, Michael (Technical Monitor); Smith, Davey; Metzgar, David; Wills, Christopher; Fierer, Joshua

    2002-01-01

    Saccharomyces cerevisiae is a yeast commonly used in baking and a frequent colonizer of human mucosal surfaces. It is considered relatively nonpathogenic in immunocompetent adults. We present a case of S. cerevisiae fungemia and aortic graft infection in an immunocompetent adult. This is the first reported case of S. cerevisiue fungemia where the identity of the pathogen was confirmed by rRNA sequencing.

  4. The relevance of aortic endograft prosthetic infection

    NARCIS (Netherlands)

    Cernohorsky, Paul; Reijnen, Michel M. P. J.; Tielliu, Ignace F. J.; van Sterkenburg, Steven M. M.; van den Dungen, Jan J. A. M.; Zeebregts, Clark J.

    Background: Vascular prosthetic graft infection is a severe complication after open aortic aneurysm repair. Reports of infected endografts are scarce. General treatment consensus with infected graft material is that it should be removed completely. The objective of this study was to describe the

  5. Thrombosed false channel in acute aortic dissections

    International Nuclear Information System (INIS)

    Alerci, M.; Dore, R.; Kluzer, A.; Digiulio, G.; D'Andrea, F.; De Agostini, A.

    1987-01-01

    Three cases are reported of acute dissection with complete thrombosis of the false channel, which is a very uncommonevent in DeBakey's I and II type aortic dissections. The 3 patients entered hospital because of severe thoracic pain without any ECG sign of myocardial infarction. Emergency CT showed evidence of pericardial effusion suggesting hemopericardium, enlargement of the ascending aorta and a peripheral semilunar filling defect which caused a slight deformation of the true channel. On precontrast scans, only one case showed inward displacement of peripheral calcifications and high-density aortic wall. No tipical signs of aortic dissection were reported, expect in the first patient - where a double contrast filled lumen, separated by an intimal flap was seen. CT findings are individually discussed. It is emphasized that in all patients more than one CT sign was present at a time. The correct evaluation of these signs together with the clinacal data could lead to the right diagnosis of aortic dissection in spite of the lack of a f???

  6. Genetics Home Reference: supravalvular aortic stenosis

    Science.gov (United States)

    ... and narrower than usual. A thickened aorta is less flexible and resilient to the stress of constant blood flow and pumping of the heart. Over time, the wall of the aorta can become damaged. Aortic narrowing causes the heart to work harder to pump blood through the aorta, resulting ...

  7. Dynamic renal scintigraphy in aortic disorders

    International Nuclear Information System (INIS)

    Terae, Satoshi; Itoh, Kazuo; Tsukamoto, Eriko; Nakada, Kunihiro; Fujimori, Kenji; Hashimoto, Masato; Tanabe, Tatsuzo; Furudate, Masayori; Irie, Goro

    1986-01-01

    Dynamic renal scintigraphy has been reviewed for evaluation of renal arterial involvement in aortic disorders such as arteriosclerosis obliterans, abdominal aortic aneurysm and dissecting aneurysm. As a diagnostic finding and parameters, we used blood perfusion images of both kidneys and relative split renal function index obtained with analysis of the time-activity curves which were generated using a renal region of interest. In the diagnosis of unilateral renal arterial involvement, sensitivity and specificity of blood perfusion images were 100 % (9/9) and 77 % (10/13) and those of relative split renal function index were 78 % (7/9) and 92 % (12/13), respectively. Dynamic renal scintigraphy was useful for evaluating unilateral renal arterial involvement in aortic diseases. However, scintigraphic diagnosis of bilateral renal arterial involvement were difficult. And in a severe case, we could not differentiate renal parenchymal damage due to renovascular involvement from senile renal dysfunction or hypertensive renal disease which is often a cause of aortic disorders. (author)

  8. Rotating ring-ring electrode theory and experiment

    NARCIS (Netherlands)

    Kuiken, H.K.; Bakkers, E.P.A.M.; Ligthart, H.; Kellyb, J.J.

    2000-01-01

    A model is presented for the rotating ring-ring electrode. Although the electrode is defined by four characteristic lengths, it is shown that the collection efficiency depends on only two dimensionless parameters. A simple relationship between these and the corresponding parameters for the rotating

  9. The Rotating Ring-Ring Electrode. Theory and Experiment

    NARCIS (Netherlands)

    Kuiken, H.K.; Bakkers, E.P.A.M.; Ligthart, H.; Kelly, J.J.

    2000-01-01

    A model is presented for the rotating ring-ring electrode. Although the electrode is defined by four characteristic lengths, it is shown that the collection efficiency depends on only two dimensionless parameters. A simple relationship between these and the corresponding parameters for the rotating

  10. Aortic root reconstruction by aortic valve-sparing operation (David type I reimplantation) in Marfan syndrome accompanied by annuloaortic ectasia and acute type-A aortic dissection.

    Science.gov (United States)

    Inamura, Shunichi; Furuya, Hidekazu; Yagi, Kentarou; Ikeya, Eriko; Yamaguchi, Masaomi; Fujimura, Takabumi; Kanabuchi, Kazuo

    2006-09-20

    To reconstruct the aortic root for aneurysm of the ascending aorta accompanied by aortic regurgitation, annuloaortic ectasia (AAE) and acute type-A dissection with root destruction, the Bentall operation using a prosthetic valve still is the standard procedure today. Valve-sparing procedures have actively been used for aortic root lesions, and have also been attempted in aortic root reconstruction for Marfan syndrome which may have abnormalities in the valve leaflets. We conducted a valve-sparing procedure in a female patient with Marfan syndrome who had AAE accompanied by type-A acute aortic dissection. The patient was a 37-year-old woman complaining of severe pain from the chest to the back. The limbs were long, and funnel breast was observed. Diastolic murmurs were heard. On chest computed tomography, a dissection cavity was present from the ascending aorta to the left common iliac artery, and the root dilated to 55 mm. Grade II aortic regurgitation was observed on ultrasound cardiography. Regarding her family history, her father had died suddenly at 54 years of age. She was diagnosed with type-A acute dissection concurrent with Marfan syndrome and AAE. The structure of the aortic valve was normal, and root reconstruction by a valve-sparing operation and total replacement of the aortic arch was conducted. On postoperative ultrasound cardiography, the aortic regurgitation was within the allowable range, and the shortterm postoperative results were good.

  11. Multimodality Imaging Approach towards Primary Aortic Sarcomas Arising after Endovascular Abdominal Aortic Aneurysm Repair: Case Series Report

    Energy Technology Data Exchange (ETDEWEB)

    Kamran, Mudassar, E-mail: kamranm@mir.wustl.edu; Fowler, Kathryn J., E-mail: fowlerk@mir.wustl.edu; Mellnick, Vincent M., E-mail: mellnickv@mir.wustl.edu [Washington University School of Medicine, Mallinckrodt Institute of Radiology (United States); Sicard, Gregorio A., E-mail: sicard@wudosis.wustl.edu [Washington University School of Medicine, Department of Surgery (United States); Narra, Vamsi R., E-mail: narrav@mir.wustl.edu [Washington University School of Medicine, Mallinckrodt Institute of Radiology (United States)

    2016-06-15

    Primary aortic neoplasms are rare. Aortic sarcoma arising after endovascular aneurysm repair (EVAR) is a scarce subset of primary aortic malignancies, reports of which are infrequent in the published literature. The diagnosis of aortic sarcoma is challenging due to its non-specific clinical presentation, and the prognosis is poor due to delayed diagnosis, rapid proliferation, and propensity for metastasis. Post-EVAR, aortic sarcomas may mimic other more common aortic processes on surveillance imaging. Radiologists are rarely knowledgeable about this rare entity for which multimodality imaging and awareness are invaluable in early diagnosis. A series of three pathologically confirmed cases are presented to display the multimodality imaging features and clinical presentations of aortic sarcoma arising after EVAR.

  12. In vivo transfer of cholesteryl ester from high and low density plasma lipoproteins into human aortic tissue

    International Nuclear Information System (INIS)

    Stender, S.; Hjelms, E.

    1988-01-01

    For the study of cholesteryl ester transfer from different plasma lipoproteins into human aortic tissue, patients scheduled for reconstructive aortic surgery were intravenously injected with autologous in vitro labeled lipoproteins 20 to 24 hours before aortic intima-media samples were obtained during the operation. The injectate contained high density lipoproteins (d greater than 1.063) labeled with 3H-cholesteryl ester and lipoproteins of lower density (d less than 1.063) labeled with 14C-cholesteryl ester or lipoproteins with the opposite labeling. In 16 aortic tissue samples (some with visible atherosclerosis) from 11 normocholesterolemic patients, the aortic influx of total cholesteryl ester was 1 to 50 nmol x cm-2 x day-1. Some 39% +/- 3% (mean +/- SEM) of the influx was derived from high density lipoproteins, which in plasma accounted for only 22% +/- 2% (mean +/- SEM) of the esterified cholesterol. The findings suggest that: 1) esterified cholesterol from the two lipoprotein fractions in plasma enter the aortic intima by the same mechanism, and 2) influx of cholesteryl ester from the smaller, high density lipoproteins is greater than influx from the larger, lower density lipoproteins considering their concentrations in plasma. In some patients, the cholesterol content in the intima-media tissue with no visible atherosclerosis corresponded to only a few months of continuous cholesteryl ester influx. This time is short considering the age of the patients and, therefore, indicates that removal of esterified cholesterol from the intima-media is of major importance in preventing cholesterol deposition in the arterial wall

  13. Damping rings for CLIC

    CERN Document Server

    Jowett, John M; Zimmermann, Frank; Owen, H

    2001-01-01

    The Compact Linear Colider (CLIC) is designed to operate at 3 TeV centre-of-mass energy with a total luminosity of 10^35 cm^-2 s^-1. The overall system design leads to extremely demanding requirements on the bunch trains injected into the main libac at frequency of 100 Hz. In particular, the emittances of the intense bunches have to be about an order of magnitude smaller than presently achieved. We describe our approach to finding a damping ring design capable of meeting these requirements. Besides lattice design, emittance and damping rate considerations, a number of scattering and instability effects have to be incorporated into the optimisation of parameters. Among these, intra-bem scattering and the electron cloud effect are two of the most significant.

  14. Does the sun ring

    International Nuclear Information System (INIS)

    Isaak, G.R.

    1978-01-01

    The work of various groups, which have been investigating the possibility of measuring the periodicities of solar oscillations in an attempt to test theoretical models of the sun, is reported. In particular the observation of small velocity oscillations of the surface layers of the sun that permits the measurement of the sound waves (or phonons) in the solar atmosphere, is discussed. Oscillations with periods of 2.65 h, 58 and 40 min and amplitudes of 2.7, 0.8 and 0.7 ms -1 respectively are reported. Support for a periodicity at about 2.65 h from a number of other groups using other measuring techniques are considered. It is felt that the most probable interpretation of the observed solar oscillations is that the sun is a resonator which is ringing. (UK)

  15. Aortic valve-sparing operations in aortic root aneurysms: remodeling or reimplantation?

    Science.gov (United States)

    Rahnavardi, Mohammad; Yan, Tristan D; Bannon, Paul G; Wilson, Michael K

    2011-08-01

    A best evidence topic was written according to a structured protocol. The question addressed was whether the reimplantation (David) technique or the remodeling (Yacoub) technique provides the optimum event free survival in patients with an aortic root aneurysm suitable for an aortic valve-sparing operation. In total, 392 papers were found using the reported search criteria, of which 14 papers provided the best evidence to answer the clinical question. A total of 1338 patients (Yacoub technique in 606 and David technique in 732) from 13 centres were included. In most series, cardiopulmonary bypass time and aortic cross-clamp time were longer for the David technique compared to the Yacoub technique. Early mortality was comparable between the two techniques (0-6.9% for the Yacoub technique and 0-6% for the David technique). There is a tendency for a higher freedom from significant long-term aortic insufficiency in the David group than the Yacoub group, which does not necessarily result in a higher reoperation rate in the Yacoub group. In the largest series reported, freedom from a moderate-to-severe aortic insufficiency at 12 years was 82.6 ± 6.2% in the Yacoub and 91.0 ± 3.8% in the David group (P=0.035). Freedom from reoperation at the same time point was 90.4 ± 4.7% in the Yacoub group and 97.4 ± 2.2% in the David group (P=0.09). In another series, freedom from reoperation at a follow-up time of about four years was 89 ± 4% in the Yacoub group and 98 ± 2% in the David group. Although some authors merely preferred the Yacoub technique for a bicuspid aortic valve, the accumulated evidence in the current review indicates comparable results for both techniques in a bicuspid aortic valve. Current evidence is in favour of the David rather than the Yacoub technique in pathologies such as Marfan syndrome, acute type A aortic dissection, and excessive annular dilatation that may impair aortic root integrity. Careful selection of patients for each technique and

  16. Cardiovascular effects of a herbicide containing glufosinate and a surfactant: in vitro and in vivo analyses in rats.

    Science.gov (United States)

    Koyama, K; Koyama, K; Goto, K

    1997-08-01

    A herbicide, Basta (BASTA), containing glufosinate ammonium (GLA) as the main component and an anionic surfactant, sodium polyoxyethylene alkylether sulfate (AES), causes hemodynamic changes characterized by a decrease in total vascular resistance with an increase or a decrease in cardiac output in human acute oral poisoning. With a motivation based on these clinical observations, we tried to elucidate the exact component and its mode of action that is mostly responsible for the direct cardiovascular effects of this herbicide formulation, investigating the effects of BASTA, GLA, and AES independently on the cardiovascular system in rats in vitro and in vivo. In isolated right atria beating spontaneously in Krebs-Ringer's solution, BASTA and AES produced negative chronotropic responses in a concentration-dependent manner. In electrically driven isolated left atria, BASTA and AES produced positive inotropic responses concentration dependently but negative inotropic responses at extremely high concentrations. In aortic ring segments, BASTA and AES produced no vasoconstrictive effects but exerted significant vasodilative effects when the aortic ring was precontracted with phenylephrine. These in vitro responses caused by BASTA and AES occurred to a similar degree. On the other hand, the main component, GLA, produced no effects in isolated atria and aortas. In anesthetized rats, relatively low doses of BASTA and AES produced a decrease in blood pressure followed by a slight increase in heart rate, which was presumably due to baroreflex caused by the decrease in blood pressure. At an extremely high dose, BASTA and AES produced a decrease in blood pressure with a marked decrease in heart rate. These in vivo responses to BASTA and AES also occurred to a similar degree. In contrast, the main component, GLA, did not produce any effects on heart rate and blood pressure in anesthetized rats. From these results, we concluded that the effects of BASTA in our in vivo experiments

  17. Antiangiogenic Activity of Acer tegmentosum Maxim Water Extract in Vitro and in Vivo.

    Science.gov (United States)

    Kim, Eok-Cheon; Kim, So Hun; Piao, Shan-Ji; Kim, Tack-Joong; Bae, Kiho; Kim, Han Sung; Hong, Soon-Sun; Lee, Byoung Ick; Nam, Moonsuk

    2015-07-01

    Angiogenesis, the formation of new blood vessels, is critical for tumor growth and metastasis. Notably, tumors themselves can lead to angiogenesis by inducing vascular endothelial growth factor (VEGF), which is one of the most potent angiogenic factors. Inhibition of angiogenesis is currently perceived as one of the most promising strategies for the blockage of tumor growth. In this study, we investigated the effects of Acer tegmentosum maxim water extract (ATME) on angiogenesis and its underlying signal mechanism. We studied the antiangiogenic activity of ATME by using human umbilical vein endothelial cells (HUVECs). ATME strongly inhibited VEGF-induced endothelial cell proliferation, migration, invasion, and tube formation, as well as vessel sprouting in a rat aortic ring sprouting assay. Moreover, we found that the p44/42 mitogen activated protein (MAP) kinase signaling pathway is involved in the inhibition of angiogenesis by ATME. Moreover, when we performed the in vivo matrigel plug assay, VEGF-induced angiogenesis was potently reduced when compared to that for the control group. Taken together, these results suggest that ATME exhibits potent antiangiogenic activity in vivo and in vitro and that these effects are regulated by the extracellular regulated kinase (ERK) pathway.

  18. Chromosome aberrations in monkey lymphocytes irradiated in vitro and in vivo

    International Nuclear Information System (INIS)

    Ziemba-Zak, B.

    1976-01-01

    The relationship between the X-ray dose and yield of dicentrics plus centric rings in monkey lymphocytes in vitro was studied. Frequency of these aberrations at different periods after in vivo exposure was also studied. No statistically significant differences were found between the yield of dicentrics plus centric rings obtained by in vitro and in vivo (up to 7 days) after irradiation. (author)

  19. How Jupiter's Ring Was Discovered.

    Science.gov (United States)

    Elliot, James; Kerr, Richard

    1985-01-01

    "Rings" (by astronomer James Elliot and science writer Richard Kerr) is a nontechnical book about the discovery and exploration of ring systems from the time of Galileo to the era of the Voyager spacecraft. One of this book's chapters is presented. (JN)

  20. Pyrimidine-pyridine ring interconversion

    NARCIS (Netherlands)

    Plas, van der H.C.

    2003-01-01

    This chapter discusses the pyrimidine-to-pyridine ring transformation and pyridine-to-pyrimidine ring transformation. In nucleophile-induced pyrimidine-to-pyridine rearrangements, two types of reactions can be distinguished depending on the structure of the nucleophile: (1) reactions in which the

  1. Duplo arco aórtico: a quebra do silêncio Double aortic arch: the break of silence

    Directory of Open Access Journals (Sweden)

    Ana Rita Abrão

    2011-03-01

    Full Text Available Anéis vasculares representam 1-2% dos casos das cardiopatias congênitas. Relatamos um caso raro de duplo arco aórtico. Mulher, 60 anos, procurou atendimento na clínica médica apresentando 1 ano de história de disfagia, 6 meses de dispneia e 2 meses de dor torácica esporádica. Raio X de tórax revelou: hiperinsuflação pulmonar difusa, alargamento mediastinal, coração com volume e configurações normais, arco aórtico à direita e alterações degenerativas vertebrais. Tomografia computadorizada do tórax: arco aórtico duplo circundando e comprimindo a traqueia e o esôfago. Arco direito mais calibroso, emergindo dele o tronco braquiocefálico. Do arco esquerdo emergem a artéria carótida comum e a subclávia esquerda. Diagnóstico: anel vascular traqueoesofagiano decorrente do duplo arco aórtico, sendo o arco direito dominante. No presente caso, optou-se por seguimento clínico da paciente, levando-se em conta a intensidade dos sintomas apresentados.Vascular rings represent 1 to 2% of cases of congenital heart disease. We report a rare case of double aortic arch. A 60-year-old woman was admitted to the hospital presenting a one-year history of dysphagia, six months of dyspnea and two months of sporadic chest pain. Radiograph of the chest revealed diffuse pulmonary hyper inflation, widening of the mediastinum, heart of normal size and shape, a right-sized aortic arch, and degenerative changes of the thoracic spine. Computed tomography of the chest showed a double aortic arch encircling and compressing the trachea and the esophagus. The right aortic arch had a larger caliber, with brachiocephalic trunk arising from it. The left common carotid artery and the left subclavian artery arose from the left aortic arch. Diagnosis: tracheoesophageal vascular ring due to double aortic arch, with dominant right arch. In this case, we chose to follow the patient medically, taking into consideration the mildness of the symptoms.

  2. High Fat Diet Attenuates the Anticontractile Activity of Aortic PVAT via a Mechanism Involving AMPK and Reduced Adiponectin Secretion

    Directory of Open Access Journals (Sweden)

    Tarek A. M. Almabrouk

    2018-02-01

    Full Text Available Background and aim: Perivascular adipose tissue (PVAT positively regulates vascular function through production of factors such as adiponectin but this effect is attenuated in obesity. The enzyme AMP-activated protein kinase (AMPK is present in PVAT and is implicated in mediating the vascular effects of adiponectin. In this study, we investigated the effect of an obesogenic high fat diet (HFD on aortic PVAT and whether any changes involved AMPK.Methods: Wild type Sv129 (WT and AMPKα1 knockout (KO mice aged 8 weeks were fed normal diet (ND or HFD (42% kcal fat for 12 weeks. Adiponectin production by PVAT was assessed by ELISA and AMPK expression studied using immunoblotting. Macrophages in PVAT were identified using immunohistochemistry and markers of M1 and M2 macrophage subtypes evaluated using real time-qPCR. Vascular responses were measured in endothelium-denuded aortic rings with or without attached PVAT. Carotid wire injury was performed and PVAT inflammation studied 7 days later.Key results: Aortic PVAT from KO and WT mice was morphologically indistinct but KO PVAT had more infiltrating macrophages. HFD caused an increased infiltration of macrophages in WT mice with increased expression of the M1 macrophage markers Nos2 and Il1b and the M2 marker Chil3. In WT mice, HFD reduced the anticontractile effect of PVAT as well as reducing adiponectin secretion and AMPK phosphorylation. PVAT from KO mice on ND had significantly reduced adiponectin secretion and no anticontractile effect and feeding HFD did not alter this. Wire injury induced macrophage infiltration of PVAT but did not cause further infiltration in KO mice.Conclusions: High-fat diet causes an inflammatory infiltrate, reduced AMPK phosphorylation and attenuates the anticontractile effect of murine aortic PVAT. Mice lacking AMPKα1 phenocopy many of the changes in wild-type aortic PVAT after HFD, suggesting that AMPK may protect the vessel against deleterious changes in response to

  3. Brief report: biomarkers of aortic vascular prosthetic graft infection in a porcine model with Staphylococcus aureus

    DEFF Research Database (Denmark)

    Langerhuus, S. N.; Tønnesen, E. K.; Jensen, K. H.

    2010-01-01

    Aortic vascular prosthetic graft infection (AVPGI) with Staphylococcus aureus is a feared post-operative complication. This study was conducted to evaluate the clinical signs and potential biomarkers of infection in a porcine AVPGI model. The biomarkers evaluated were: C-reactive protein (CRP......), fibrinogen, white blood cells (WBC), major histocompatibility complex II (MHC II) density, lymphocyte CD4:CD8 ratio and tumour necrosis factor-alpha (TNF-α) in vitro responsiveness. Sixteen pigs were included in the study, and randomly assigned into four groups (n = 4): “SHAM” pigs had their infra...

  4. Hemoglobin induces monocyte recruitment and CD163-macrophage polarization in abdominal aortic aneurysm

    DEFF Research Database (Denmark)

    Rubio-Navarro, Alfonso; Amaro Villalobos, Juan Manuel; Lindholt, Jes S

    2015-01-01

    BACKGROUND: Increased hemoglobin (Hb) accumulation was reported in abdominal aortic aneurysms (AAAs). CD163 is a macrophage receptor involved in tissue Hb clearance, however its role in AAA has not been reported. We investigated the role of Hb on monocyte recruitment and differentiation towards CD......163 expressing macrophages ex vivo, in vitro and in human AAA. METHODS AND RESULTS: CD163 mRNA and protein expression was significantly higher in human AAA (n=7) vs. healthy wall (n=6). CD163 was predominantly found in adventitia of AAA, coinciding with areas rich in hemosiderin and adjacent...

  5. Binomial Rings: Axiomatisation, Transfer and Classification

    OpenAIRE

    Xantcha, Qimh Richey

    2011-01-01

    Hall's binomial rings, rings with binomial coefficients, are given an axiomatisation and proved identical to the numerical rings studied by Ekedahl. The Binomial Transfer Principle is established, enabling combinatorial proofs of algebraical identities. The finitely generated binomial rings are completely classified. An application to modules over binomial rings is given.

  6. A High Performance Pulsatile Pump for Aortic Flow Experiments in 3-Dimensional Models.

    Science.gov (United States)

    Chaudhury, Rafeed A; Atlasman, Victor; Pathangey, Girish; Pracht, Nicholas; Adrian, Ronald J; Frakes, David H

    2016-06-01

    Aortic pathologies such as coarctation, dissection, and aneurysm represent a particularly emergent class of cardiovascular diseases. Computational simulations of aortic flows are growing increasingly important as tools for gaining understanding of these pathologies, as well as for planning their surgical repair. In vitro experiments are required to validate the simulations against real world data, and the experiments require a pulsatile flow pump system that can provide physiologic flow conditions characteristic of the aorta. We designed a newly capable piston-based pulsatile flow pump system that can generate high volume flow rates (850 mL/s), replicate physiologic waveforms, and pump high viscosity fluids against large impedances. The system is also compatible with a broad range of fluid types, and is operable in magnetic resonance imaging environments. Performance of the system was validated using image processing-based analysis of piston motion as well as particle image velocimetry. The new system represents a more capable pumping solution for aortic flow experiments than other available designs, and can be manufactured at a relatively low cost.

  7. Aortic events in a nationwide Marfan syndrome cohort.

    Science.gov (United States)

    Groth, Kristian A; Stochholm, Kirstine; Hove, Hanne; Kyhl, Kasper; Gregersen, Pernille A; Vejlstrup, Niels; Østergaard, John R; Gravholt, Claus H; Andersen, Niels H

    2017-02-01

    Marfan syndrome is associated with morbidity and mortality due to aortic dilatation and dissection. Preventive aortic root replacement has been the standard treatment in Marfan syndrome patients with aortic dilatation. In this study, we present aortic event data from a nationwide Marfan syndrome cohort. The nationwide cohort of Danish Marfan syndrome patients was established from the Danish National Patient Registry and the Cause of Death Register, where we retrieved information about aortic surgery and dissections. We associated aortic events with age, sex, and Marfan syndrome diagnosis prior or after the first aortic event. From the total cohort of 412 patients, 150 (36.4 %) had an aortic event. Fifty percent were event free at age 49.6. Eighty patients (53.3 %) had prophylactic surgery and seventy patients (46.7 %) a dissection. The yearly event rate was 0.02 events/year/patient in the period 1994-2014. Male patients had a significant higher risk of an aortic event at a younger age with a hazard ratio of 1.75 (CI 1.26-2.42, p = 0.001) compared with women. Fifty-three patients (12.9 %) were diagnosed with MFS after their first aortic event which primarily was aortic dissection [n = 44 (83.0 %)]. More than a third of MFS patients experienced an aortic event and male patients had significantly more aortic events than females. More than half of the total number of dissections was in patients undiagnosed with MFS at the time of their event. This emphasizes that diagnosing MFS is lifesaving and improves mortality risk by reducing the risk of aorta dissection.

  8. The risk for type B aortic dissection in Marfan syndrome.

    Science.gov (United States)

    den Hartog, Alexander W; Franken, Romy; Zwinderman, Aeilko H; Timmermans, Janneke; Scholte, Arthur J; van den Berg, Maarten P; de Waard, Vivian; Pals, Gerard; Mulder, Barbara J M; Groenink, Maarten

    2015-01-27

    Aortic dissections involving the descending aorta are a major clinical problem in patients with Marfan syndrome. The purpose of this study was to identify clinical parameters associated with type B aortic dissection and to develop a risk model to predict type B aortic dissection in patients with Marfan syndrome. Patients with the diagnosis of Marfan syndrome and magnetic resonance imaging or computed tomographic imaging of the aorta were followed for a median of 6 years for the occurrence of type B dissection or the combined end point of type B aortic dissection, distal aortic surgery, and death. A model using various clinical parameters as well as genotyping was developed to predict the risk for type B dissection in patients with Marfan syndrome. Between 1998 and 2013, 54 type B aortic dissections occurred in 600 patients with Marfan syndrome (mean age 36 ± 14 years, 52% male). Independent variables associated with type B aortic dissection were prior prophylactic aortic surgery (hazard ratio: 2.1; 95% confidence interval: 1.2 to 3.8; p = 0.010) and a proximal descending aorta diameter ≥27 mm (hazard ratio: 2.2; 95% confidence interval: 1.1 to 4.3; p = 0.020). In the risk model, the 10-year occurrence of type B aortic dissection in low-, moderate-, and high-risk patients was 6%, 19%, and 34%, respectively. Angiotensin II receptor blocker therapy was associated with fewer type B aortic dissections (hazard ratio: 0.3; 95% confidence interval: 0.1 to 0.9; p = 0.030). Patients with Marfan syndrome with prior prophylactic aortic surgery are at substantial risk for type B aortic dissection, even when the descending aorta is only slightly dilated. Angiotensin II receptor blocker therapy may be protective in the prevention of type B aortic dissections. Copyright © 2015 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

  9. Ionization cooling ring for muons

    Directory of Open Access Journals (Sweden)

    R. Palmer

    2005-06-01

    Full Text Available Practical ionization cooling rings could lead to lower cost or improved performance in neutrino factory or muon collider designs. The ring modeled here uses realistic three-dimensional fields. The performance of the ring compares favorably with the linear cooling channel used in the second U.S. Neutrino Factory Study. The normalized 6D emittance of an ideal ring is decreased by a factor of approximately 240, compared with a factor of only 15 for the linear channel. We also examine such real-world effects as windows on the absorbers and rf cavities and leaving empty lattice cells for injection and extraction. For realistic conditions the ring decreases the normalized 6D emittance by a factor of 49.

  10. Selective Aortic Arch and Root Replacement in Repair of Acute Type A Aortic Dissection.

    Science.gov (United States)

    Fleischman, Fernando; Elsayed, Ramsey S; Cohen, Robbin G; Tatum, James M; Kumar, S Ram; Kazerouni, Kayvan; Mack, Wendy J; Barr, Mark L; Cunningham, Mark J; Hackmann, Amy E; Baker, Craig J; Starnes, Vaughn A; Bowdish, Michael E

    2018-02-01

    Controversy exists regarding the optimal extent of repair for type A aortic dissection. Our approach is to replace the ascending aorta, and only replace the aortic root or arch when intimal tears are present in those areas. We examined intermediate outcomes with this approach to acute type A aortic dissection repair. Between March 2005 and October 2016, 195 patients underwent repair of acute type A aortic dissection. Repair was categorized by site of proximal and distal anastomosis and extent of repair. Mean follow-up was 31.0 ± 30.9 months. Kaplan-Meier analysis was used to assess survival. Multiple variable Cox proportional hazards modeling was utilized to identify factors associated with overall mortality. Overall survival was 85.1%, 83.9%, 79.1%, and 74.4% at 6, 12, 36, and 60 months, respectively. Eight patients required reintervention. The cumulative incidence of aortic reintervention at 1 year with death as a competing outcome was 3.95%. Multiple variable regression analysis identified factors such as age, preoperative renal failure, concomitant thoracic endograft, postoperative myocardial infarction and sepsis, and need for extracorporeal membrane oxygenation as predictive of overall mortality. Neither proximal or distal extent of repair, nor need for reintervention affected overall survival (proximal: hazard ratio 1.63, 95% confidence interval: 0.75 to 3.51, p = 0.22; distal: hazard ratio 1.12, 95% confidence interval: 0.43 to 2.97, p = 0.81; reintervention: hazard ratio 0.03, 95% confidence interval: 0.002 to 0.490, p < 0.01). A selective approach to root and arch repair in acute type A aortic dissection is safe. If aortic reintervention is needed, survival does not appear to be affected. Copyright © 2018 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

  11. Percutaneous implantation of the first repositionable aortic valve prosthesis in a patient with severe aortic stenosis.

    Science.gov (United States)

    Buellesfeld, Lutz; Gerckens, Ulrich; Grube, Eberhard

    2008-04-01

    Percutaneous aortic valve replacement is a new less-invasive alternative for high-risk surgical candidates with aortic stenosis. However, the clinical experience is still limited, and the currently available 'first-generation devices' revealed technical shortcomings, such as lack of repositionability and presence of paravalvular leakages. We report the first-in-man experience with the new self-expanding Lotus Valve prosthesis composed of a nitinol frame with implemented bovine pericardial leaflets which is designed to address these issues, being repositionable and covered by a flexible membrane to seal paravalvular gaps. We implanted this prosthesis in a 93-year old patient presenting with severe symptomatic aortic stenosis (valve area: 0.6 cm(2)). Surgical valve replacement had been declined due to comorbidities. We used a retrograde approach for insertion of the 21-French Lotus catheter loaded with the valve prosthesis via surgical cut-down to the external iliac artery. Positioning of the valve was guided by transesophageal echo and supra-aortic angiograms. The prosthesis was successfully inserted and deployed within the calcified native valve. Echocardiography immediately after device deployment showed a significant reduction of the transaortic mean pressure gradient (32 to 9 mmHg; final valve area 1.7 cm(2)) without evidence of residual aortic regurgitation. The postprocedural clinical status improved from NYHA-IV to NYHA-II. These results remained unchanged up to the 3 month follow-up. Successful percutaneous aortic valve replacement can be performed using the new self-expanding and repositionable Lotus valve for treatment of high-risk patients with aortic valve stenosis. Further studies are mandatory to assess device safety and efficacy in larger patient populations. Copyright 2008 Wiley-Liss, Inc.

  12. Relation of thoracic aortic and aortic valve calcium to coronary artery calcium and risk assessment.

    Science.gov (United States)

    Wong, Nathan D; Sciammarella, Maria; Arad, Yadon; Miranda-Peats, Romalisa; Polk, Donna; Hachamovich, Rory; Friedman, John; Hayes, Sean; Daniell, Anthony; Berman, Daniel S

    2003-10-15

    Aortic calcium, aortic valve calcium (AVC), and coronary artery calcium (CAC) have been associated with cardiovascular event risk. We examined the prevalence of thoracic aortic calcium (TAC) and AVC in relation to the presence and extent of CAC, cardiovascular risk factors, and estimated risk of coronary heart disease (CHD). In 2,740 persons without known CHD aged 20 to 79 years, CAC was assessed by electron beam- or multidetector-computed tomography. We determined the prevalence of TAC and AVC in relation to CAC, CHD risk factors, and predicted 10-year risk of CHD. A close correspondence of TAC and AVC was observed with CAC. TAC and AVC increased with age; by the eighth decade of life, the prevalence of TAC was similar to that of CAC (>80%), and 36% of men and 24% of women had AVC. Age, male gender, and low-density lipoprotein cholesterol were directly related to the likelihood of CAC, TAC, and AVC; higher diastolic blood pressure and cigarette smoking additionally predicted CAC. Body mass index and higher systolic and lower diastolic blood pressures were also related to TAC, and higher body mass index and lower diastolic blood pressure were related to AVC. Calculated risk of CHD increased with the presence of AVC and TAC across levels of CAC. TAC and AVC provided incremental value over CAC in association with the 10-year calculated risk of CHD. If longitudinal studies show an incremental value of aortic and aortic valve calcium over that of CAC for prediction of cardiovascular events, future guidelines for risk assessment incorporating CAC assessment may additionally incorporate the measurement of aortic and/or aortic valve calcium.

  13. Abnormalities of aortic arch shape, central aortic flow dynamics, and distensibility predispose to hypertension after successful repair of aortic coarctation.

    Science.gov (United States)

    Donazzan, Luca; Crepaz, Robert; Stuefer, Josef; Stellin, Giovanni

    2014-10-01

    Systemic hypertension (HT) is a major long-term complication even after successful repair of aortic coarctation (CoA), and many factors are involved in this pathophysiology. To investigate the role of abnormalities in the aortic arch shape, central aortic flow dynamics, and distensibility in developing HT after successful repair of CoA. We selected a group of 26 normotensive patients (mean age 16.9±7.3 years, range 9-32 years) with anatomically successful repair of CoA among 140 patients regularly followed after repair of CoA and analyzed their last clinical and echocardiographic data. Bicycle exercise test and ambulatory blood pressure monitoring (ABPM) were also obtained. Mean age at surgical repair was 3.2±3.9 years (range 10 days-15 years); 12 patients underwent surgical correction during the first year of life. Repair of CoA was performed by end-to-end anastomosis (TT) in 23 patients (extended TT in 6 patients with arch hypoplasia), patch aortoplasty in 2, and subcalvian flap aortoplasty in 1. The postsurgical follow-up was 13.8±7.2 years (range 3.5-29.4 years). The shape of the aortic arch was defined by magnetic resonance imaging (MRI) on this global geometry (normal-gothic-crenel), ratio of the height-transverse diameter (A/T), percentage of residual stenosis, and growth index of the transverse arch segments. Flow mapping by phase-contrast imaging in the ascending and descending aorta was performed in order to measure the systolic waveforms and central aortic distensibility. Twenty normal age-matched patients submitted to the same MRI protocol were used as controls. Six patients were found to have a gothic and 20 a normal aortic arch shape. Patients with gothic aortic arch shape had an increased A/T ratio (0.80±0.07 vs 0.58±0.05, P135 mm Hg on ABPM were higher in the gothic than in the normal arch group. There was a correlation between nocturnal SBP, 24 hours pulse pressure on ABPM in the whole group, and different MRI variables (A/T, distensibility of

  14. Evaluation of ring impedance of the Photon Factory storage ring

    International Nuclear Information System (INIS)

    Kiuchi, T.; Izawa, M.; Tokumoto, S.; Hori, Y.; Sakanaka, S.; Kobayashi, M.; Kobayakawa, H.

    1992-05-01

    The loss parameters of the ducts in the Photon Factory (PF) storage ring were evaluated using the wire method and the code TBCI. Both the measurement and the calculation were done for a different bunch length (σ) ranging from 23 to 80 ps. The PF ring impedance was estimated to be |Z/n|=3.2 Ω using the broadband impedance model. The major contribution to the impedance comes from the bellows and the gate valve sections. Improvements of these components will lower the ring impedance by half. (author)

  15. Detecting atheromatous plaques in the aortic arch or supra-aortic arteries for more accurate stroke subtype classification.

    Science.gov (United States)

    Cui, Xiaoyang; Wu, Simiao; Zeng, Quantao; Xiao, Jiahe; Liu, Ming

    2015-02-01

    To investigate the correlations of atheromatous plaques in the aortic arch or supra-aortic arteries with intracranial arterial stenosis and carotid plaques in stroke patients, and to determine whether taking these plaques into account will reduce the proportion of patients in the undetermined etiology group. We prospectively enrolled 308 ischemic stroke patients, whose clinical characteristics and A-S-C-O classifications were compared with analyses of intracranial arteries, carotid arteries, aortic arch, and supra-aortic arteries. 125(40.6%) patients had plaques in the aortic arch or supra-aortic arteries, of which 106 (84.8%) had complex plaques. No correlations were observed between these plaques and carotid plaques ( p = 0.283) or intracranial arterial stenosis ( p = 0.097). After detecting the mobile thrombi in the aortic arch and supra-aortic arteries, the proportion of patients in the atherothrombosis group was increased from 33.8% to 55.5% ( p = 0.00), whereas the proportion of patients in stroke of undetermined etiology group was decreased from 19.2% to 11.0% ( p = 0.00). Examining only the carotid and intracranial arteries may not provide adequate information about large arteries in stroke patients. Therefore, it would be better to include a search for relevant plaques in the aortic arch or supra-aortic arteries in modern stroke workup, for it may lead to more accurate stroke subtype classification and guide secondary prevention.

  16. An ex-vivo model for evaluating bioenergetics in aortic rings

    Directory of Open Access Journals (Sweden)

    Kyle P. Feeley

    2014-01-01

    Full Text Available Cardiovascular disease (CVD is the leading cause of death worldwide and it exhibits a greatly increasing incidence proportional to aging. Atherosclerosis is a chronic condition of arterial hardening resulting in restriction of oxygen delivery and blood flow to the heart. Relationships between mitochondrial DNA damage, oxidant production, and early atherogenesis have been recently established and it is likely that aspects of atherosclerotic risk are metabolic in nature. Here we present a novel method through which mitochondrial bioenergetics can be assessed from whole aorta tissue. This method does not require mitochondrial isolation or cell culture and it allows for multiple technical replicates and expedient measurement. This procedure facilitates quantitative bioenergetic analysis and can provide great utility in better understanding the link between mitochondria, metabolism, and atherogenesis.

  17. Aortic Blood Flow Reversal Determines Renal Function: Potential Explanation for Renal Dysfunction Caused by Aortic Stiffening in Hypertension.

    Science.gov (United States)

    Hashimoto, Junichiro; Ito, Sadayoshi

    2015-07-01

    Aortic stiffness determines the glomerular filtration rate (GFR) and predicts the progressive decline of the GFR. However, the underlying pathophysiological mechanism remains obscure. Recent evidence has shown a close link between aortic stiffness and the bidirectional (systolic forward and early diastolic reverse) flow characteristics. We hypothesized that the aortic stiffening-induced renal dysfunction is attributable to altered central flow dynamics. In 222 patients with hypertension, Doppler velocity waveforms were recorded at the proximal descending aorta to calculate the reverse/forward flow ratio. Tonometric waveforms were recorded to measure the carotid-femoral (aortic) and carotid-radial (peripheral) pulse wave velocities, to estimate the aortic pressure from the radial waveforms, and to compute the aortic characteristic impedance. In addition, renal hemodynamics was evaluated by duplex ultrasound. The estimated GFR was inversely correlated with the aortic pulse wave velocity, reverse/forward flow ratio, pulse pressure, and characteristic impedance, whereas it was not correlated with the peripheral pulse wave velocity or mean arterial pressure. The association between aortic pulse wave velocity and estimated GFR was independent of age, diabetes mellitus, hypercholesterolemia, and antihypertensive medication. However, further adjustment for the aortic reverse/forward flow ratio and pulse pressure substantially weakened this association, and instead, the reverse/forward flow ratio emerged as the strongest determinant of estimated GFR (P=0.001). A higher aortic reverse/forward flow ratio was also associated with lower intrarenal forward flow velocities. These results suggest that an increase in aortic flow reversal (ie, retrograde flow from the descending thoracic aorta toward the aortic arch), caused by aortic stiffening and impedance mismatch, reduces antegrade flow into the kidney and thereby deteriorates renal function. © 2015 American Heart Association

  18. Acute Type A Aortic Dissection Successfully Managed with One-stage Surgery of Total Aortic Arch Replacement with Supra-aortic Transposition Plus Frozen Elephant Trunk Technique

    Directory of Open Access Journals (Sweden)

    Meng-Lin Lee

    2014-09-01

    Full Text Available Acute type A aortic dissection has long been a challenging issue. The surgical techniques traditionally vary with the anatomic extent of the aortic dissection. Simple ascending aortic grafting can be lifesaving, but the lesions beyond the aorta, which include the arch vessels and descending aorta, remain potential hazards. In this paper, we present a patient in which acute type A aortic dissection with lesions extending into descending thoracic aorta was successfully managed by total arch replacement with supra-aortic transposition plus the frozen elephant trunk technique to the descending aorta. A 67-year-old gentleman presented with severe tearing pain from the anterior to posterior chest. Computed tomography confirmed the diagnosis of acute type A dissection extending to the level of the right common iliac artery. An emergent operation was performed as in the aforementioned technique. The surgery went well and the patient was discharged without comorbidities on postoperative day 25. The patient had regular outpatient clinical follow-up. The follow-up computed tomography images showed adequate results with the obliteration of the false lumen. In conclusion, total aortic arch replacement with supra-aortic transposition plus frozen elephant trunk technique is a safe and feasible operative method for patients with detrimental acute type A aortic dissection.

  19. 3D echocardiographic analysis of aortic annulus for transcatheter aortic valve replacement using novel aortic valve quantification software: Comparison with computed tomography.

    Science.gov (United States)

    Mediratta, Anuj; Addetia, Karima; Medvedofsky, Diego; Schneider, Robert J; Kruse, Eric; Shah, Atman P; Nathan, Sandeep; Paul, Jonathan D; Blair, John E; Ota, Takeyoshi; Balkhy, Husam H; Patel, Amit R; Mor-Avi, Victor; Lang, Roberto M

    2017-05-01

    With the increasing use of transcatheter aortic valve replacement (TAVR) in patients with aortic stenosis (AS), computed tomography (CT) remains the standard for annulus sizing. However, 3D transesophageal echocardiography (TEE) has been an alternative in patients with contraindications to CT. We sought to (1) test the feasibility, accuracy, and reproducibility of prototype 3DTEE analysis software (Philips) for aortic annular measurements and (2) compare the new approach to the existing echocardiographic techniques. We prospectively studied 52 patients who underwent gated contrast CT, procedural 3DTEE, and TAVR. 3DTEE images were analyzed using novel semi-automated software designed for 3D measurements of the aortic root, which uses multiplanar reconstruction, similar to CT analysis. Aortic annulus measurements included area, perimeter, and diameter calculations from these measurements. The results were compared to CT-derived values. Additionally, 3D echocardiographic measurements (3D planimetry and mitral valve analysis software adapted for the aortic valve) were also compared to the CT reference values. 3DTEE image quality was sufficient in 90% of patients for aortic annulus measurements using the new software, which were in good agreement with CT (r-values: .89-.91) and small (software can accurately measure aortic annulus in patients with severe AS undergoing TAVR, in better agreement with CT than the existing methodology. Accordingly, intra-procedural TEE could potentially replace CT in patients where CT carries significant risk. © 2017, Wiley Periodicals, Inc.

  20. Tinkering at the main-ring lattice

    Energy Technology Data Exchange (ETDEWEB)

    Ohnuma, S.

    1982-08-23

    To improve production of usable antiprotons using the proton beam from the main ring and the lossless injection of cooled antiprotons into the main ring, modifications of the main ring lattice are recommended.

  1. Is the bell ringing?

    CERN Multimedia

    Francesco Poppi

    2010-01-01

    During the Nobel prize-winning UA1 experiment, scientists in the control room used to ring a bell if a particularly interesting event had occurred. Today, the “CMS Exotica hotline” routine produces a daily report that lists the exotic events that were recorded the day before.   Display of an event selected by the Exotica routine. Take just a very small fraction of the available data (max. 5%); define the events that you want to keep and set the parameters accordingly; run the Exotica routine and only look at the very few images that the system has selected for you. This is the recipe that a small team of CMS researchers has developed to identify the signals coming from possible new physics processes. “This approach does not replace the accurate data analysis on the whole set of data. However, it is a very fast and effective way to focus on just a few events that are potentially very interesting”, explains Maurizio Pierini (CERN), who developed the...

  2. Can early aortic root surgery prevent further aortic dissection in Marfan syndrome?

    Science.gov (United States)

    Shimizu, Hideyuki; Kasahara, Hirofumi; Nemoto, Atsushi; Yamabe, Kentaro; Ueda, Toshihiko; Yozu, Ryohei

    2012-02-01

    We reviewed 50 patients with Marfan syndrome who underwent surgery for aortic root pathologies comprising a root aneurysm without (n = 25; group A) and with (n = 25; group B) dissection. Aortic root repair included Bentall (n = 37) and valve-sparing (n = 13) procedures. Hospital mortality was 4.0%. Twenty-two patients required 36 repeat surgeries on the distal aorta. The main indication for re-intervention was the dilation of the false lumen. In group A, the distal aorta was stable for up to 7 years, but new dissection developed in 5 (33.3%) of the 15 patients who were followed up for >7 years after the root repair. Actuarial survival including operative mortality was 88.1 and 65.0% at 10 and 20 years, respectively; groups A and B did not significantly differ. Rates of freedom from all-cause death, new dissection or repeated aortic surgery were 60.1, 44.5 and 26.0% at 5, 10 and 15 years, respectively. Group A was significantly better than group B. Prophylactic aortic root repair apparently reduces the likelihood of overall adverse events, but it cannot guarantee the prevention of further aortic dissection. A multidisciplinary approach is needed for patients with Marfan syndrome.

  3. Endovascular Treatment of Late Thoracic Aortic Aneurysms after Surgical Repair of Congenital Aortic Coarctation in Childhood

    Science.gov (United States)

    Juszkat, Robert; Perek, Bartlomiej; Zabicki, Bartosz; Trojnarska, Olga; Jemielity, Marek; Staniszewski, Ryszard; Smoczyk, Wiesław; Pukacki, Fryderyk

    2013-01-01

    Background In some patients, local surgery-related complications are diagnosed many years after surgery for aortic coarctation. The purposes of this study were: (1) to systematically evaluate asymptomatic adults after Dacron patch repair in childhood, (2) to estimate the formation rate of secondary thoracic aortic aneurysms (TAAs) and (3) to assess outcomes after intravascular treatment for TAAs. Methods This study involved 37 asymptomatic patients (26 female and 11 male) who underwent surgical repair of aortic coarctation in the childhood. After they had reached adolescence, patients with secondary TAAs were referred to endovascular repair. Results Follow-up studies revealed TAA in seven cases (19%) (including six with the gothic type of the aortic arch) and mild recoarctation in other six (16%). Six of the TAA patients were treated with stentgrafts, but one refused to undergo an endovascular procedure. In three cases, stengrafts covered the left subclavian artery (LSA), in another the graft was implanted distally to the LSA. In two individuals, elective hybrid procedures were performed with surgical bypass to the supraaortic arteries followed by stengraft implantation. All subjects survived the secondary procedures. One patient developed type Ia endoleak after stentgraft implantation that was eventually treated with a debranching procedure. Conclusions The long-term course of clinically asymptomatic patients after coarctation patch repair is not uncommonly complicated by formation of TAAs (particularly in individuals with the gothic pattern of the aortic arch) that can be treated effectively with stentgrafts. However, in some patients hybrid procedures may be necessary. PMID:24386233

  4. 'Generalizability' of a radial-aortic transfer function for the derivation of central aortic waveform parameters.

    Science.gov (United States)

    Hope, Sarah A; Meredith, Ian T; Tay, David; Cameron, James D

    2007-09-01

    Arterial transfer functions (TFs) describe the relationship between the pressure waveform at different arterial sites. Generalized TFs are used to reconstruct central aortic waveforms from non-invasively obtained peripheral waveforms and have been promoted as potentially clinically useful. A limitation is the paucity of information on their 'generalizability' with no information existing on the number of subjects required to construct a satisfactory TF, nor is adequate prospective validation available. We therefore investigated the uniformity of radial-aortic TFs and prospectively estimated the capacity of a generalized TF to reconstruct individual central blood pressure parameters. Ninety-three subjects (64 male) were studied by simultaneous radial applanation and high-fidelity (Millar Mikro-tip catheter) direct measurement of central aortic BP during elective coronary procedures. Subjects were prospectively randomized to either a derivation or validation group. Increasing numbers of individual TFs from the derivation group were averaged to form a generalized TF. There was minimal change with greater than 20 TFs averaged. In the validation group, the error in most reconstructed parameters related to the absolute value of the directly measured parameter [systolic blood pressure (SBP) and pulse pressure, Pcentral aortic SBP and pulse pressure (negatively) and time to peak systole (positively) (all PInclusion of more than 20 individual TFs in the construction of a generalized TF does not improve 'generalizability'. There appear to be systematic errors in derived central pressure waveforms and derived aortic augmentation index is inaccurate compared to the directly measured value.

  5. The changing course of aortic valve disease in Scotland: temporal trends in hospitalizations and mortality and prognostic importance of aortic stenosis.

    Science.gov (United States)

    Berry, Colin; Lloyd, Suzanne M; Wang, Yanzhong; Macdonald, Alyson; Ford, Ian

    2013-06-01

    To investigate the contemporary clinical course of aortic valve disease types. We performed a retrospective population-level epidemiological study of hospitalized care in Scotland from 1 January 1997 to 31 December 2005 using electronic case identification of hospital admissions and deaths. Time-to-event analyses were performed using Cox Proportional-Hazards models. A total of 19 733 adults with an index hospitalization and a final diagnosis of non-congenital aortic valve disease were identified. Aortic stenosis, aortic insufficiency, mixed aortic valve disease, or unspecified aortic valve disease occurred in 13 220 (67.0%), 2807 (14.2%), 699 (3.5%), and 3007 (15.2%), individuals, respectively. The majority of hospitalizations occurred in elderly persons aged 80 and older. In total, 9981 (50.6%) patients had died by 31 December 2006. When compared with aortic stenosis, the risk of death was less with aortic insufficiency [hazard ratio (95% confidence interval) 0.79 (0.74, 0.84)] and mixed aortic valve disease [0.83 (0.74, 0.93)]. Female gender, admission year, and hypertension were associated with lower mortality in patients with aortic stenosis. Patients with aortic stenosis had increased risk of death or heart failure (adjusted P valve replacement of whom 73.2% had aortic stenosis, 11.9% aortic valve disease (unspecified),10.0% aortic insufficiency, and 4.9% aortic stenosis with insufficiency. Patients with aortic stenosis with insufficiency had increased likelihood of aortic valve replacement [1.19 (1.02, 1.38)]. Age, female gender, and co-morbidity reduced the likelihood of aortic valve replacement. The incidence of aortic valve stenosis has substantially increased in Scotland in recent years. Aortic stenosis predicts morbidity and mortality when compared with other types of aortic valve disease.

  6. Moving ring reactor 'Karin-1'

    International Nuclear Information System (INIS)

    1983-12-01

    The conceptual design of a moving ring reactor ''Karin-1'' has been carried out to advance fusion system design, to clarify the research and development problems, and to decide their priority. In order to attain these objectives, a D-T reactor with tritium breeding blanket is designed, a commercial reactor with net power output of 500 MWe is designed, the compatibility of plasma physics with fusion engineering is demonstrated, and some other guideline is indicated. A moving ring reactor is composed mainly of three parts. In the first formation section, a plasma ring is formed and heated up to ignition temperature. The plasma ring of compact torus is transported from the formation section through the next burning section to generate fusion power. Then the plasma ring moves into the last recovery section, and the energy and particles of the plasma ring are recovered. The outline of a moving ring reactor ''Karin-1'' is described. As a candidate material for the first wall, SiC was adopted to reduce the MHD effect and to minimize the interaction with neutrons and charged particles. The thin metal lining was applied to the SiC surface to solve the problem of the compatibility with lithium blanket. Plasma physics, the engineering aspect and the items of research and development are described. (Kako, I.)

  7. Factors associated with the development of aortic valve regurgitation over time after two different techniques of valve-sparing aortic root surgery.

    Science.gov (United States)

    Hanke, Thorsten; Charitos, Efstratios I; Stierle, Ulrich; Robinson, Derek; Gorski, Armin; Sievers, Hans-H; Misfeld, Martin

    2009-02-01

    Early results after aortic valve-sparing root reconstruction are excellent. Longer-term follow-up, especially with regard to aortic valve function, is required for further judgment of these techniques. Between July of 1993 and September of 2006, 108 consecutive patients (mean age 53.0 +/- 15.8 years) underwent the Yacoub operation (group Y) and 83 patients underwent the David operation (group D). Innovative multilevel hierarchic modeling methods were used to analyze aortic regurgitation over time. In general, aortic regurgitation increased with time in both groups. Factors associated with the development of a significant increase in aortic regurgitation were Marfan syndrome, concomitant cusp intervention, and preoperative aortic anulus dimension. In Marfan syndrome, the initial aortic regurgitation was higher in group Y versus group D (0.56 aortic regurgitation vs 0.29 aortic regurgitation, P = .049), whereas the mean annual progression rate of aortic regurgitation was marginally higher in group Y (0.132 aortic regurgitation vs 0.075 aortic regurgitation, P = .1). Concomitant cusp intervention was associated with a significant aortic regurgitation increase in both groups (P Marfan syndrome and a large preoperative aortic annulus diameter were better treated with the reimplantation technique, whereas those with a smaller diameter were better treated with the remodeling technique. Concomitant free-edge plication of prolapsing cusps was disadvantageous in both groups. Considering these factors may serve to improve the aortic valve longevity after valve-sparing aortic root surgery.

  8. Quantum Fourier Transform Over Galois Rings

    OpenAIRE

    Zhang, Yong

    2009-01-01

    Galois rings are regarded as "building blocks" of a finite commutative ring with identity. There have been many papers on classical error correction codes over Galois rings published. As an important warm-up before exploring quantum algorithms and quantum error correction codes over Galois rings, we study the quantum Fourier transform (QFT) over Galois rings and prove it can be efficiently preformed on a quantum computer. The properties of the QFT over Galois rings lead to the quantum algorit...

  9. Aortic dissection presenting as a febrile disease and atrial fibrillation

    OpenAIRE

    Blas-Macedo, Jorge; Márquez-Ramírez, Dolores; Gómez-Dominguez, José de Jesús

    2007-01-01

    Aortic dissection is a cardiovascular emergency. Its main manifestation is severe chest pain, and approximately 50% of patients present with an elevated systemic blood pressure. Rare reported physical findings include a pulsatile sterno-clavicular joint, dysphagia or testicular tenderness. The absence of sudden onset of pain lowers the likelihood of aortic dissection. We describe a patient in whom aortic dissection was accompanied by fever, nightsweats, suprasternal pain and atrial fibrillati...

  10. Diminutive Porcelain Ascending Aorta With Supravalvular Aortic Stenosis.

    Science.gov (United States)

    Houmsse, Mustafa; McDavid, Asia; Kilic, Ahmet

    2018-05-01

    This report describes the case of a 49-year-old man with a medical history significant for congenital aortic stenosis. The patient presented with progressive shortness of breath and decreased stamina and was found to have a concentric, diminutive porcelain ascending aorta with diffuse supravalvular aortic stenosis. We describe treatment with an aortic root augmentation and Bentall procedure using hypothermic circulatory arrest. Copyright © 2018 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

  11. Transcatheter aortic valve prosthesis surgically replaced 4 months after implantation

    DEFF Research Database (Denmark)

    Thyregod, Hans Gustav; Lund, Jens Teglgaard; Engstrøm, Thomas

    2010-01-01

    Transcatheter aortic valve implantation is a new and rapidly evolving treatment option for high-risk surgical patients with degenerative aortic valve stenosis. Long-term results with these new valve prostheses are lacking, and potential valve dysfunction and failure would require valve replacemen....... We report the first case of surgical valve replacement in a patient with a dysfunctional transcatheter-implanted aortic valve prosthesis 4 months after implantation....

  12. Single Coronary Artery with Aortic Regurgitation

    International Nuclear Information System (INIS)

    Katsetos, Manny C.; Toce, Dale T.

    2003-01-01

    An isolated single coronary artery can be associated with normal life expectancy; however, patients are at an increased risk of sudden death. A case is reported of a 54-year-old man with several months of chest pressure with activity. On exercise Sestamibi stress testing, the patient developed a hypotensive response with no symptoms and minimal electrocardiographic changes. Nuclear scanning demonstrated reversible septal and lateral perfusion defects consistent with severe ischemia. Coronary angiography revealed a single coronary artery with the right coronary artery arising from the left main. There were high-grade stenotic lesions in the left anterior descending and circumflex arteries with only moderate atherosclerotic disease in the right coronary artery. An aortogram showed 2-3+ aortic regurgitation, with an ejection fraction of 45% on ventriculography. The patient underwent four-vessel revascularization and aortic valve replacement and did well postoperatively

  13. Diagnosis of aortic interruption by CT angiography

    International Nuclear Information System (INIS)

    Shirani, Shapour; Soleymanzadeh, Maryam

    2013-01-01

    Interrupted aortic arch (IAA) is a rare congenital malformation of the aortic arch, which might be accompanied with other coexisting cardiovascular anomalies. Many cases with IAA are diagnosed at their neonatal and newborn period but in rare cases the diagnosis is not established until adulthood. The patients may have no clinical symptoms but the signs of heart failure will gradually appear and may cause death. The development of imaging methods such as computed tomography (CT) and magnetic resonance (MR) imaging has dramatically changed the diagnostics. Here we report a 20-year-old young man with IAA associated with sinus venosus atrial septal defect (SVD) and partial anomalous pulmonary venous connection (PAPVC) referred to our hospital

  14. Suprarenal Abdominal Aortic Coarctation Diagnosed During Pregnancy

    Directory of Open Access Journals (Sweden)

    Sh Hajsadeghi

    2010-12-01

    Full Text Available Coarctation of the abdominal aorta is an extremely rare vascular defect inwhich congenital or acquired etiologies have been described. This case concernsa 30-year-old pregnant woman with 15-years history of uncontrolled hypertensionand lower limb claudication presented with worsened hypertension during herfirst pregnancy. Magnetic resonance angiography study of aorta revealed astenosis in abdominal aorta about 12mm from the origin of celiac axisaccompanied by left sided aortic arch and right aberrant subclavian artery. Thiscase highlights the importance of a throughout physical examination in patientspresented with hypertension and it emphasizes considering the coarctation of theabdominal aorta during the diagnostic workup of hypertension, especially inyoung patients. In such cases magnetic resonance angiography of the aorta is auseful tool to reach a definitive diagnosis especially in pregnant women.Also to our knowledge, this patient is the first one found to have aortic archmalformation combined with an abdominal coarctation.

  15. Transcatheter aortic valve implantation and cerebrovascular accidents.

    Science.gov (United States)

    Stortecky, Stefan; Wenaweser, Peter; Windecker, Stephan

    2012-09-01

    Transcatheter aortic valve implantation (TAVI) is an evidence-based treatment alternative for selected high-risk patients with symptomatic severe aortic stenosis as acknowledged in the most recent edition of the ESC Guidelines on Valvular Heart Disease 2012. However, periprocedural complications and in particular cerebrovascular accidents remain a matter of concern. While transcatheter heart valve technology continuously improves and the development of novel and even less invasive implantation techniques is on-going, cerebrovascular events complicating TAVI may abrogate the usual improvement in terms of prognosis and quality of life. This article describes the incidence of cerebrovascular events after cardiovascular procedures, provides an overview of the pathophysiological mechanisms as well as the impact on outcomes and provides some insights into preventive strategies as well as the acute management of these events.

  16. Spontaneous aortic dissecting hematoma in two dogs.

    Science.gov (United States)

    Boulineau, Theresa Marie; Andrews-Jones, Lydia; Van Alstine, William

    2005-09-01

    This report describes 2 cases of spontaneous aortic dissecting hematoma in young Border Collie and Border Collie crossbred dogs. Histology was performed in one of the cases involving an unusual splitting of the elastin present within the wall of the aorta, consistent with elastin dysplasia as described in Marfan syndrome in humans. The first case involved a young purebred Border Collie that died suddenly and the second case involved a Border Collie crossbred dog that died after a 1-month history of seizures. Gross lesions included pericardial tamponade with dissection of the ascending aorta in the former case and thoracic cavity hemorrhage, mediastinal hematoma, and aortic dissection in the latter. Histologic lesions in the case of the Border Collie crossbred dog included a dissecting hematoma of the ascending aorta with elastin dysplasia and right axillary arterial intimal proliferation.

  17. Polarized particles in storage rings

    International Nuclear Information System (INIS)

    Derbenev, Ya.S.; Kondratenko, A.M.; Serednyakov, S.I.; Skrinskij, A.N.; Tumajkin, G.M.; Shatunov, Yu.M.

    1977-01-01

    Experiments with polarized beams on the VEPP-2M and SPEAK storage rings are described. Possible methods of producing polarized particle beams in storage rings as well as method of polarization monitoring are counted. Considered are the processes of radiation polarization of electrons and positrons. It is shown, that to preserve radiation polarization the introduction of regions with a strong sign-variable magnetic field is recommended. Methods of polarization measurement are counted. It is suggested for high energies to use dependence of synchrotron radiation power on transverse polarization of electrons and positrons. Examples of using polarizability of colliding beams in storage rings are presented

  18. Researches on the Piston Ring

    Science.gov (United States)

    Ehihara, Keikiti

    1944-01-01

    In internal combustion engines, steam engines, air compressors, and so forth, the piston ring plays an important role. Especially, the recent development of Diesel engines which require a high compression pressure for their working, makes, nowadays, the packing action of the piston ring far more important than ever. Though a number of papers have been published in regard to researches on the problem of the piston ring, none has yet dealt with an exact measurement of pressure exerted on the cylinder wall at any given point of the ring. The only paper that can be traced on this subject so far is Mr. Nakagawa's report on the determination of the relative distribution of pressure on the cylinder wall, but the measuring method adopted therein appears to need further consideration. No exact idea has yet been obtained as to how the obturation of gas between the piston and cylinder, the frictional resistance of the piston, and the wear of the cylinder wall are affected by the intensity and the distribution of the radial pressure of the piston ring. Consequently, the author has endeavored, by employing an apparatus of his own invention, to get an exact determination of the pressure distribution of the piston ring. By means of a newly devised ring tester, to which piezoelectricity of quartz was applied, the distribution of the radial pressure of many sample rings on the market was accurately determined. Since many famous piston rings show very irregular pressure distribution, the author investigated and achieved a manufacturing process of the piston ring which will exert uniform pressure on the cylinder wall. Temperature effects on the configuration and on the mean spring power have also been studied. Further, the tests were performed to ascertain how the gas tightness of the piston ring may be affected by the number or spring power. The researches as to the frictional resistance between the piston ring and the cylinder wall were carried out, too. The procedure of study, and

  19. Soft Congruence Relations over Rings

    Science.gov (United States)

    Xin, Xiaolong; Li, Wenting

    2014-01-01

    Molodtsov introduced the concept of soft sets, which can be seen as a new mathematical tool for dealing with uncertainty. In this paper, we initiate the study of soft congruence relations by using the soft set theory. The notions of soft quotient rings, generalized soft ideals and generalized soft quotient rings, are introduced, and several related properties are investigated. Also, we obtain a one-to-one correspondence between soft congruence relations and idealistic soft rings and a one-to-one correspondence between soft congruence relations and soft ideals. In particular, the first, second, and third soft isomorphism theorems are established, respectively. PMID:24949493

  20. Distributively generated matrix near rings

    International Nuclear Information System (INIS)

    Abbasi, S.J.

    1993-04-01

    It is known that if R is a near ring with identity then (I,+) is abelian if (I + ,+) is abelian and (I,+) is abelian if (I*,+) is abelian [S.J. Abbasi, J.D.P. Meldrum, 1991]. This paper extends these results. We show that if R is a distributively generated near ring with identity then (I,+) is included in Z(R), the center of R, if (I + ,+) is included in Z(M n (R)), the center of matrix near ring M n (R). Furthermore (I,+) is included in Z(R) if (I*,+) is included in Z(M n (R)). (author). 5 refs

  1. SMARANDACHE NON-ASSOCIATIVE RINGS

    OpenAIRE

    Vasantha, Kandasamy

    2002-01-01

    An associative ring is just realized or built using reals or complex; finite or infinite by defining two binary operations on it. But on the contrary when we want to define or study or even introduce a non-associative ring we need two separate algebraic structures say a commutative ring with 1 (or a field) together with a loop or a groupoid or a vector space or a linear algebra. The two non-associative well-known algebras viz. Lie algebras and Jordan algebras are mainly built using a vecto...

  2. Aortic valve replacement during acute rheumatic fever.

    Science.gov (United States)

    Khan, A; Chi, S; Gonzalez-Lavin, L

    1978-07-01

    Emergency aortic valve replacement was performed during an attack of acute rheumatic fever in a 12-year-old black boy. He had an uneventful recovery and has remained asymptomatic 27 months after operation. In the light of this experience and that of others, one might conclude that the decision to operate on these patients should be based on the severity of the haemodynamic derangement rather than on the state of activity in the rheumatic process.

  3. Total Percutaneous Aortic Repair: Midterm Outcomes

    International Nuclear Information System (INIS)

    Bent, Clare L.; Fotiadis, Nikolas; Renfrew, Ian; Walsh, Michael; Brohi, Karim; Kyriakides, Constantinos; Matson, Matthew

    2009-01-01

    The purpose of this study was to examine the immediate and midterm outcomes of percutaneous endovascular repair of thoracic and abdominal aortic pathology. Between December 2003 and June 2005, 21 patients (mean age: 60.4 ± 17.1 years; 15 males, 6 females) underwent endovascular stent-graft insertion for thoracic (n = 13) or abdominal aortic (n = 8) pathology. Preprocedural computed tomographic angiography (CTA) was performed to assess the suitability of aorto-iliac and common femoral artery (CFA) anatomy, including the degree of CFA calcification, for total percutaneous aortic stent-graft repair. Percutaneous access was used for the introduction of 18- to 26-Fr delivery devices. A 'preclose' closure technique using two Perclose suture devices (Perclose A-T; Abbott Vascular) was used in all cases. Data were prospectively collected. Each CFA puncture site was assessed via clinical examination and CTA at 1, 6, and 12 months, followed by annual review thereafter. Minimum follow-up was 36 months. Outcome measures evaluated were rates of technical success, conversion to open surgical repair, complications, and late incidence of arterial stenosis at the site of Perclose suture deployment. A total of 58 Perclose devices were used to close 29 femoral arteriotomies. Outer diameters of stent-graft delivery devices used were 18 Fr (n = 5), 20 Fr (n = 3), 22 Fr (n = 4), 24 Fr (n = 15), and 26 Fr (n = 2). Percutaneous closure was successful in 96.6% (28/29) of arteriotomies. Conversion to surgical repair was required at one access site (3.4%). Mean follow-up was 50 ± 8 months. No late complications were observed. By CT criteria, no patient developed a >50% reduction in CFA caliber at the site of Perclose deployment during the study period. In conclusion, percutaneous aortic stent-graft insertion can be safely performed, with a low risk of both immediate and midterm access-related complications.

  4. Paradoxical aortic stenosis: A systematic review.

    Science.gov (United States)

    Cavaca, Rita; Teixeira, Rogério; Vieira, Maria João; Gonçalves, Lino

    2017-04-01

    Aortic stenosis (AS) is a complex systemic valvular and vascular disease with a high prevalence in developed countries. The new entity "paradoxical low-flow, low-gradient aortic stenosis" refers to cases in which patients have severe AS based on assessment of aortic valve area (AVA) (≤1 cm 2 ) or indexed AVA (≤0.6 cm 2 /m 2 ), but paradoxically have a low mean transvalvular gradient (<40 mmHg) and a low stroke volume index (≤35 ml/m 2 ), despite preserved left ventricular ejection fraction (≥50%). A search was carried out in the PubMed database on paradoxical AS for the period 2007-2014. A total of 57 articles were included for this review. The prevalence of paradoxical AS ranged from 3% to 35% of the population with severe degenerative AS. It was more frequent in females and in older patients. Paradoxical AS was associated with characteristic left ventricular remodeling as well as an increase in systemic arterial stiffness. It was noted that there may be errors and inaccuracies in the calculation of AVA by the continuity equation, which could erroneously suggest the paradoxical phenotype. There are new diagnostic methods to facilitate the study of AS, such as aortic valve calcium score, valvuloarterial impedance and the longitudinal mechanics of the left ventricle. With regard to its natural history, it is not clear whether paradoxical AS corresponds to an advance stage of the disease or if paradoxical AS patients have a distinct phenotype with specific characteristics. Valve replacement, either surgical or percutaneous, may be indicated in patients with severe and symptomatic paradoxical AS. Copyright © 2016 Sociedade Portuguesa de Cardiologia. Publicado por Elsevier España, S.L.U. All rights reserved.

  5. Relationship between aortic diseases and renal cysts

    International Nuclear Information System (INIS)

    Hashizume, Toshikazu

    2009-01-01

    Based on empirical observations, patients with aortic diseases (AoD) (abdominal aortic aneurysm (AAA), thoracic aortic aneurysm (TAA) and aortic dissection (AD)) appeared to present with an increased incidence of renal cysts (RC) observed on computed tomography (CT). To clarify any potential relationship, I compared incidence of RC on CT scans in patients with and without AoD. A comparison was conducted on the incidence of RC on CT scans in 107 patients (74.6 years old; n=71 males, n=36 females) with AoD (57 AAA, 36 TAA, 14 AD) versus 332 control patients (73.6 years old; n=193 males, n=139 females) without AoD. Univariate analysis and multiple logistic regression were performed to evaluate the relationship between AoD and RC incidence. In patients with AoD, 65.0% presented with RC compared to only 28.6% in the control group (p<0.0001). In comparison, the AoD group presented with a higher frequency of hypertension (63.6% vs. 33.4%, p<0.0001), coronary artery disease (26.2% vs. 13.6%, p<0.0001), chronic obstructive pulmonary disease (COPD) (10.3% vs. 4.2%, p<0.0001), but no significant frequency of dyslipidemia and diabetes mellitus was observed between the 2 groups. Multivariate analysis indicated three independent predictors of AoD: hypertension (p=0.013; odds ratio=2.32), COPD (p=0.015; odds ratio=5.62) and RC (p<0.0001; odds ratio=4.88). These results indicate a significantly higher incidence of RC in patients with versus without AoD. A close relationship between AoD and RC may exist, and coincidental RC could be a potential indicator for AoD screening. (author)

  6. Relationship between aortic diseases and renal cysts

    Energy Technology Data Exchange (ETDEWEB)

    Hashizume, Toshikazu [Minami Wakayama Medical Center, Tanabe, Wakayama (Japan)

    2009-12-15

    Based on empirical observations, patients with aortic diseases (AoD) (abdominal aortic aneurysm (AAA), thoracic aortic aneurysm (TAA) and aortic dissection (AD)) appeared to present with an increased incidence of renal cysts (RC) observed on computed tomography (CT). To clarify any potential relationship, I compared incidence of RC on CT scans in patients with and without AoD. A comparison was conducted on the incidence of RC on CT scans in 107 patients (74.6 years old; n=71 males, n=36 females) with AoD (57 AAA, 36 TAA, 14 AD) versus 332 control patients (73.6 years old; n=193 males, n=139 females) without AoD. Univariate analysis and multiple logistic regression were performed to evaluate the relationship between AoD and RC incidence. In patients with AoD, 65.0% presented with RC compared to only 28.6% in the control group (p<0.0001). In comparison, the AoD group presented with a higher frequency of hypertension (63.6% vs. 33.4%, p<0.0001), coronary artery disease (26.2% vs. 13.6%, p<0.0001), chronic obstructive pulmonary disease (COPD) (10.3% vs. 4.2%, p<0.0001), but no significant frequency of dyslipidemia and diabetes mellitus was observed between the 2 groups. Multivariate analysis indicated three independent predictors of AoD: hypertension (p=0.013; odds ratio=2.32), COPD (p=0.015; odds ratio=5.62) and RC (p<0.0001; odds ratio=4.88). These results indicate a significantly higher incidence of RC in patients with versus without AoD. A close relationship between AoD and RC may exist, and coincidental RC could be a potential indicator for AoD screening. (author)

  7. Vascular complications associated with transcatheter aortic valve replacement.

    Science.gov (United States)

    Sardar, M Rizwan; Goldsweig, Andrew M; Abbott, J Dawn; Sharaf, Barry L; Gordon, Paul C; Ehsan, Afshin; Aronow, Herbert D

    2017-06-01

    Transcatheter aortic valve replacement (TAVR) is now an accepted pathway for aortic valve replacement for patients who are at prohibitive, severe and intermediate risk for traditional aortic valve surgery. However, with this rising uptrend and adaptation of this new technology, vascular complications and their management remain an Achilles heel for percutaneous aortic valve replacement. The vascular complications are an independent predictor of mortality for patients undergoing TAVR. Early recognition of these complications and appropriate management is paramount. In this article, we review the most commonly encountered vascular complications associated with currently approved TAVR devices and their optimal percutaneous management techniques.

  8. Possible Subclinical Leaflet Thrombosis in Bioprosthetic Aortic Valves

    DEFF Research Database (Denmark)

    Makkar, Raj R; Fontana, Gregory; Jilaihawi, Hasan

    2015-01-01

    BACKGROUND: A finding of reduced aortic-valve leaflet motion was noted on computed tomography (CT) in a patient who had a stroke after transcatheter aortic-valve replacement (TAVR) during an ongoing clinical trial. This finding raised a concern about possible subclinical leaflet thrombosis...... patients and 1 of 115 patients, respectively; P=0.007). CONCLUSIONS: Reduced aortic-valve leaflet motion was shown in patients with bioprosthetic aortic valves. The condition resolved with therapeutic anticoagulation. The effect of this finding on clinical outcomes including stroke needs further...

  9. The Effects of Fetuin-A Levels on Aortic Stenosis

    Directory of Open Access Journals (Sweden)

    Ahmet Tutuncu

    2016-07-01

    Full Text Available Aim: We aimed to investigate the relation between fetuin-A and calcific aortic stenosis in non diabetic patients whose renal function were normal. Material and Method: 26 patients followed for aortic stenosis by our cardiology clinic for outpatients and 25 voluntary healthy subjects were included in the study. The fetuin%u2013A levels were measured from the venous blood samples of the study population. All patients underwent transthorasic echocardiography, the aortic valvular area and left ventricular parameters of the patients were measured. Results: The average age of the patients in degenerative aortic stenosis group was significantly higher than the control group. The parameters related to aortic valve were naturally higher in patients with dejenerative aortic valve. There was no siginificant difference between two groups about fetuin-A levels. Further more there was no significant relation between fetuin-a levels and aortic stenosis severity. Discussion: In conclusion fetuin-A is a multifunctional glycoprotein that plays important role in systemic calcification inhibition and valvular calcification. Finally aortic stenosis is an active process and larger studies that investigate the relation between fetuin-a and the progression and prognosis of aortic stenosis are needed.

  10. Aortic root abscess resulting from endocarditis: spectrum of angiographic findings

    International Nuclear Information System (INIS)

    Miller, S.W.; Dinsmore, R.E.

    1984-01-01

    Abscesses in the aortic root are a serious complication of infective endocarditis and require accurate diagnosis for antibiotic and surgical management. Nineteen cases of endocarditis of a native valve or prosthetic valve and adjacent abscess cavities were identified with angiography. Of 6 patients with endocarditis of a native valve, 5 had bicuspid aortic valves and all had severe aortic regurgitation. Of 13 patients with endocarditis of a prosthetic aortic valve, all had paravalvular regurgitation. Fistulas were detected into the mitral anulus in 8 patients, and into the right ventricle in 3 patients. No complications from the catheterization were recorded during the 48-hour follow-up

  11. Aortic Disease in the Young: Genetic Aneurysm Syndromes, Connective Tissue Disorders, and Familial Aortic Aneurysms and Dissections

    Directory of Open Access Journals (Sweden)

    Marcelo Cury

    2013-01-01

    Full Text Available There are many genetic syndromes associated with the aortic aneurysmal disease which include Marfan syndrome (MFS, Ehlers-Danlos syndrome (EDS, Loeys-Dietz syndrome (LDS, familial thoracic aortic aneurysms and dissections (TAAD, bicuspid aortic valve disease (BAV, and autosomal dominant polycystic kidney disease (ADPKD. In the absence of familial history and other clinical findings, the proportion of thoracic and abdominal aortic aneurysms and dissections resulting from a genetic predisposition is still unknown. In this study, we propose the review of the current genetic knowledge in the aortic disease, observing, in the results that the causative genes and molecular pathways involved in the pathophysiology of aortic aneurysm disease remain undiscovered and continue to be an area of intensive research.

  12. Aortic aneurysm disease vs. aortic occlusive disease - differences in outcome and intensive care resource utilisation after elective surgery

    DEFF Research Database (Denmark)

    Bisgaard, Jannie; Gilsaa, Torben; Rønholm, Ebbe

    2013-01-01

    clamping is more pronounced in patients with aortic aneurysm disease, which may affect outcome. OBJECTIVES: The aim of this observational cohort study was to evaluate outcome after open elective abdominal aortic surgery, hypothesising a higher 30-day mortality, a higher incidence of postoperative organ...... dysfunction and a longer length of stay in patients with aortic aneurysm compared with aortic occlusive disease. DESIGN: Cohort observational study based on prospective registrations from national databases. SETTING: Eight Danish hospitals, including four university and four non-university centres, from 1...... or inotropes, ICU stay more than 24 h, hospital length of stay and mortality. RESULTS: Compared with aortic occlusive disease, more patients with aortic aneurysm disease had ICU stays more than 24 h (62 vs. 45%, P ...

  13. Supra-aortic interventions for endovascular exclusion of the entire aortic arch.

    Science.gov (United States)

    Andrási, Terézia B; Grossmann, Marius; Zenker, Dieter; Danner, Bernhard C; Schöndube, Friedrich A

    2017-07-01

    Our aim was to analyze the outcomes of endovascular exclusion of the entire aortic arch (proximal landing in zone 0, distal landing in zone III or beyond, after Ishimaru) in which complete surgical debranching of the supra-aortic vessels (I), endovascular supra-aortic revascularization (chimney, fenestrated, or branched grafts) with partial surgical debranching (II), or total endovascular supra-aortic revascularization (III) was additionally performed. Publications describing endovascular repair of the aortic arch (2000-2016) were systematically searched and reviewed. From a total of 53 relevant studies including 1853 patients, only 1021 patients undergoing 35 different total aortic arch procedures were found eligible for further evaluation and included in group I, II, or III (429, 190, and 402 patients, respectively). Overall early mortality was higher in group I vs groups II and III (P = .001; 1 - β = 95.6%) but exceeded in group III (18.6%) and group II (14.0%) vs group I (8.0%; P = .044; 1 - β = 57.4%) for diseases involving zone 0. Mortality was higher in all subgroups treated for zone 0 disease compared with corresponding subgroups treated for zone I to zone III disease. The incidence of cerebral ischemic events was increased in groups I and II vs group III (7.5% and 11% vs 1.7%; P = .0001) and correlated with early mortality (R 2  = .20; P = .033). The incidence of type II endoleaks and endovascular reintervention was similar between groups and correlated with each other (R 2  = .37; P = .004). Type Ia endoleak occurred more often in groups II and III than in group I (7.1% and 12.1% vs 5.8%; P = .023) and correlated with midterm mortality (R 2  = .53; P = .005). Retrograde type A dissection was low in all groups, whereas aneurysm growth was higher in group III (2.6%, 4.2%, 10.7%; P = .002), correlating with midterm mortality (R 2  = .311; P = .009). Surgical revision slightly correlated with surgical complications (R 2  = .18; P = .044

  14. Thrombocytosis following splenectomy and aortic valve replacement for idiopathic thrombocytopaenic purpura with bicuspid aortic valve

    Directory of Open Access Journals (Sweden)

    Sarika Katiyar

    2015-01-01

    Full Text Available Idiopathic thrombocytopaenic purpura (ITP patients are at high risk for complications during and after cardiac surgeries involving cardiopulmonary bypass. The main clinical problem of primary ITP is an increased risk of bleeding although bleeding may not always be present. More recently, thrombosis has become appreciated as another potential complication of the procedure. We report a 22-year-old female patient with ITP with bicuspid aortic valve and splenomegaly, who underwent uncomplicated aortic valve replacement and splenectomy simultaneously. She was readmitted with chest pain due to coronary thrombosis following splenectomy which made the management difficult. We describe our experience in managing this patient who presented with thrombotic complication rather than bleeding in post-operative period and the challenges met in maintaining appropriate anticoagulation for aortic valve replacement as well as thrombosis, post-splenectomy

  15. Delirium After Transcatheter Aortic Valve Replacement.

    Science.gov (United States)

    Giuseffi, Jennifer L; Borges, Nyal E; Boehm, Leanne M; Wang, Li; McPherson, John A; Fredi, Joseph L; Ahmad, Rashid M; Ely, E Wesley; Pandharipande, Pratik P

    2017-07-01

    Postoperative delirium is associated with increased mortality. Patients undergoing transcatheter aortic valve replacement are at risk for delirium because of comorbid conditions. To compare the incidence, odds, and mortality implications of delirium between patients undergoing transcatheter replacement and patients undergoing surgical replacement. The Richmond Agitation-Sedation Scale and the Confusion Assessment Method for the Intensive Care Unit were used to assess arousal level and delirium prospectively in all patients with severe aortic stenosis who had transcatheter or surgical aortic valve replacement at an academic medical center. Multivariable logistic regression was used to determine the relationship between procedure type and occurrence of delirium. Cox regression was used to assess the association between postoperative delirium and 6-month mortality. A total of 105 patients had transcatheter replacement and 121 had surgical replacement. Patients in the transcatheter group were older (median age, 81 vs 68 years; P replacement. Delirium is less likely to develop in the transcatheter group but is associated with higher mortality in both groups. ©2017 American Association of Critical-Care Nurses.

  16. Aortic dose constraints when reirradiating thoracic tumors

    International Nuclear Information System (INIS)

    Evans, Jaden D.; Gomez, Daniel R.; Amini, Arya; Rebueno, Neal; Allen, Pamela K.; Martel, Mary K.; Rineer, Justin M.; Ang, Kie Kian; McAvoy, Sarah; Cox, James D.; Komaki, Ritsuko; Welsh, James W.

    2013-01-01

    Background and purpose: Improved radiation delivery and planning has allowed, in some instances, for the retreatment of thoracic tumors. We investigated the dose limits of the aorta wherein grade 5 aortic toxicity was observed after reirradiation of lung tumors. Material and methods: In a retrospective analysis, 35 patients were identified, between 1993 and 2008, who received two rounds of external beam irradiation that included the aorta in the radiation fields of both the initial and retreatment plans. We determined the maximum cumulative dose to 1 cm 3 of the aorta (the composite dose) for each patient, normalized these doses to 1.8 Gy/fraction, and corrected them for long-term tissue recovery between treatments (NID R ). Results: The median time interval between treatments was 30 months (range, 1–185 months). The median follow-up of patients alive at analysis was 42 months (range, 14–70 months). Two of the 35 patients (6%) were identified as having grade 5 aortic toxicities. There was a 25% rate of grade 5 aortic toxicity for patients receiving composite doses ⩾120.0 Gy (vs. 0% for patients receiving R ⩾90.0 Gy) to 1 cm 3 of the aorta

  17. Acute aortic dissection: be aware of misdiagnosis

    Directory of Open Access Journals (Sweden)

    Asteri Theodora

    2009-02-01

    Full Text Available Abstract Background Acute aortic dissection (AAD is a life-threatening condition requiring immediate assessment and therapy. A patient suffering from AAD often presents with an insignificant or irrelevant medical history, giving rise to possible misdiagnosis. The aim of this retrospective study is to address the problem of misdiagnosing AD and the different imaging studies used. Methods From January 2000 to December 2004, 49 patients (41 men and 8 women, aged from 18–75 years old presented to the Emergency Department of our hospital for different reasons and finally diagnosed with AAD. Fifteen of those patients suffered from arterial hypertension, one from giant cell arteritis and another patient from Marfan's syndrome. The diagnosis of AAD was made by chest X-ray, contrast enhanced computed tomography (CT, transthoracic echocardiography (TTE and coronary angiography. Results Initial misdiagnosis occurred in fifteen patients (31% later found to be suffering from AAD. The misdiagnosis was myocardial infarction in 12 patients and cerebral infarction in another three patients. Conclusion Aortic dissection may present with a variety of clinical manifestations, like syncope, chest pain, anuria, pulse deficits, abdominal pain, back pain, or acute congestive heart failure. Nearly a third of the patients found to be suffering from AD, were initially otherwise diagnosed. Key in the management of acute aortic dissection is to maintain a high level of suspicion for this diagnosis.

  18. Multiple subfailures characterize blunt aortic injury.

    Science.gov (United States)

    Stemper, Brian D; Yoganandan, Narayan; Pintar, Frank A; Brasel, Karen J

    2007-05-01

    Blunt aortic injuries result from rapid deceleration of the thorax as may occur during automotive impacts and falls from extreme heights. Pathological findings can range from failure of specific vessel layers to immediate vessel wall rupture. The purpose of this investigation was to determine the sequence of local structural events that may lead to aortic wall disruption. Fourteen porcine aorta specimens were opened to expose the intima and longitudinally distracted until rupture. Longitudinal mechanics were quantified and subfailures were identified. Histology was used to examine internal layer subfailure. Videography demonstrated that subfailures propagated into complete vessel wall rupture. Subfailures occurred before complete vessel rupture in 93% of specimens. Intimal and medial subfailures were present at 74% of the stress and 82% of the strain to rupture. Multiple subfailures were evident in 79% of specimens. Present results supported the clinical theory that nonimmediate death as a result of blunt aortic injury is commonly caused by propagation of lesser lesions, initiating on the intimal layer, into complete vessel rupture including the adventitial layer. This finding, along with histologic evidence of subfailure pathological findings, confirms the presence of an acute window during which recognition and initiation of permissive hypotension may be lifesaving.

  19. Preventative valve-sparing aortic root replacement and pregnancy outcome in Marfan syndrome.

    Science.gov (United States)

    Sokol, Vesna; Zlopasa, Gordan; Herman, Mislav; Planinić, Pavao; Micevska, Ana

    2012-06-01

    In Marfan syndrome, with dilatation of the aortic root secondary to an underlying connective tissue defect, pregnancy can cause hemodynamic stress leading to the development of an aortic aneurysm and even a fatal aortic dissection. In the presence of existing aortic root enlargement and a family history of aortic dissection, preventative elective surgery is suggested. Aortic root replacement with or without a valve-sparing procedure is superior to total aortic root replacement with prosthetic valve/tube graft. It provides excellent survival with low rates of aortic - valve related complications.

  20. Aortic distensibility after aortic root replacement assessed with cardiovascular magnetic resonance.

    Science.gov (United States)

    Melina, Giovanni; Rajappan, Kim; Amrani, Mohamed; Khaghani, Asghar; Pennell, Dudley J; Yacoub, Magdi H

    2002-01-01

    The changes in geometry of the aortic root during the cardiac cycle are thought to be essential for optimal valve function, both in terms of leaflet stress and dynamic behavior. Using cardiac magnetic resonance (CMR), the study aim was to determine aortic root distensibility of the homograft (group H) and the Medtronic Freestyle xenograft (group F) after aortic root replacement, from a prospective randomized trial. CMR was performed in 15 patients (six homografts, nine Freestyle) at six months and one year after surgery. Percentage change in aortic radius (PCR) and pressure strain elastic modulus (PSEM) were measured as indices of distensibility, and results related to left ventricular mass (LVM). At six months after surgery, mean PCR was 12+/-2.5 in group H and 12.9+/-6.1 in group F (p = NS), and PSEM was 428.5+/-69.8 and 493.5+/-72.7 g/cm2, respectively (p = NS). PCR was reduced to 10+/-1.7% in group H, and by 8.5+/-2.8% in group F (p = NS), while PSEM was increased to 520.5+/-87.3 and 825+/-420.4, respectively (p = NS) at the one-year follow up. Regression analysis showed a correlation between PCR and LVM (r = 0.52, p = 0.08) and LVM index (r = 0.46, p = 0.14), respectively. In addition, there was a relationship between PSEM, LVM and LVM index, suggesting that the stiffer the root wall, the higher the postoperative LVM. Up to one year after aortic root replacement, the wall of both the allogenic and xenogenic valves retained near-normal distensibility. For the first time, a correlation was demonstrated between the elastic properties of the aortic root and LVM. The longer-term behavior and clinical implications of these findings require further investigation.

  1. Blood Pressure and Arterial Load After Transcatheter Aortic Valve Replacement for Aortic Stenosis.

    Science.gov (United States)

    Lindman, Brian R; Otto, Catherine M; Douglas, Pamela S; Hahn, Rebecca T; Elmariah, Sammy; Weissman, Neil J; Stewart, William J; Ayele, Girma M; Zhang, Feifan; Zajarias, Alan; Maniar, Hersh S; Jilaihawi, Hasan; Blackstone, Eugene; Chinnakondepalli, Khaja M; Tuzcu, E Murat; Leon, Martin B; Pibarot, Philippe

    2017-07-01

    After aortic valve replacement, left ventricular afterload is often characterized by the residual valve obstruction. Our objective was to determine whether higher systemic arterial afterload-as reflected in blood pressure, pulsatile and resistive load-is associated with adverse clinical outcomes after transcatheter aortic valve replacement (TAVR). Total, pulsatile, and resistive arterial load were measured in 2141 patients with severe aortic stenosis treated with TAVR in the PARTNER I trial (Placement of Aortic Transcatheter Valve) who had systolic blood pressure (SBP) and an echocardiogram obtained 30 days after TAVR. The primary end point was 30-day to 1-year all-cause mortality. Lower SBP at 30 days after TAVR was associated with higher mortality (20.0% for SBP 100-129 mm Hg versus 12.0% for SBP 130-170 mm Hg; P <0.001). This association remained significant after adjustment, was consistent across subgroups, and confirmed in sensitivity analyses. In adjusted models that included SBP, higher total and pulsatile arterial load were associated with increased mortality ( P <0.001 for all), but resistive load was not. Patients with low 30-day SBP and high pulsatile load had a 3-fold higher mortality than those with high 30-day SBP and low pulsatile load (26.1% versus 8.1%; hazard ratio, 3.62; 95% confidence interval, 2.36-5.55). Even after relief of valve obstruction in patients with aortic stenosis, there is an independent association between post-TAVR blood pressure, systemic arterial load, and mortality. Blood pressure goals in patients with a history of aortic stenosis may need to be redefined. Increased pulsatile arterial load, rather than blood pressure, may be a target for adjunctive medical therapy to improve outcomes after TAVR. URL: http://www.clinicaltrials.gov. Unique identifier: NCT00530894. © 2017 American Heart Association, Inc.

  2. Aortic allografts in treatment of aortic valve and ascending aorta prosthetic endocarditis

    Directory of Open Access Journals (Sweden)

    S.V. Spiridonov

    2017-03-01

    Full Text Available The aim – to assess short- and long-term results of aortic root replacement using aortic allografts in patients with prosthetic endocarditis. Materials and methods. Since February 2009 until June 2016 aortic valve and ascending aorta replacement using aortic allografts was performed in 26 patients with prosthetic endocarditis. In 50 % of cases at initial operation aortic valve replacement was performed, in another 50 % of cases – aortic valve and ascending aorta replacement. Echocardiography was performed 10 days, 3, 6 and 12 months, 2, 3 and 5 years after surgery. Analysis of long-term results included all cases of deaths, prosthesis-related complications and recurrence of endocarditis. Results. 30-day mortality was 23.1 %. Extracorporeal membranous oxygenation (ECMO was used only in 5 patients (19.2 %. Four patients were weaned from ECMO. We did not observe any allograft-related complications. During follow-up period there were no cases of reoperation due to structural allograft failure. Relapse of infection occurred in 1 patient (3.8 % four years after the operation and led to lethal outcome. Conclusion. Reoperations using allografts are an effective surgical treatment of prosthetic endocarditis. In majority of cases prosthetic endocarditis was caused by gram-positive cocci (Staphylococcus. In 84.6 % of cases it was associated with destruction of paravalvular structures and abscesses formation. Heart failure was a causative factor of different complications in these patients, which required ECMO in 19.2 % of patients. In 80 % of cases patients were weaned from ECMO. Allografts using for the treatment of prosthetic endocarditis is associated with high resistance to infection and with a significant rate of freedom from recurrence of endocarditis within 3 years after surgery.

  3. Longitudinal strain predicts left ventricular mass regression after aortic valve replacement for severe aortic stenosis and preserved left ventricular function.

    Science.gov (United States)

    Gelsomino, Sandro; Lucà, Fabiana; Parise, Orlando; Lorusso, Roberto; Rao, Carmelo Massimiliano; Vizzardi, Enrico; Gensini, Gian Franco; Maessen, Jos G

    2013-11-01

    We explored the influence of global longitudinal strain (GLS) measured with two-dimensional speckle-tracking echocardiography on left ventricular mass regression (LVMR) in patients with pure aortic stenosis (AS) and normal left ventricular function undergoing aortic valve replacement (AVR). The study population included 83 patients with severe AS (aortic valve area regression (all P regression in patients with pure AS undergoing AVR. Our findings must be confirmed by further larger studies.

  4. Effect of personalized external aortic root support on aortic root motion and distension in Marfan syndrome patients.

    Science.gov (United States)

    Izgi, Cemil; Nyktari, Evangelia; Alpendurada, Francisco; Bruengger, Annina Studer; Pepper, John; Treasure, Tom; Mohiaddin, Raad

    2015-10-15

    Personalized external aortic root support (PEARS) is a novel surgical approach with the aim of stabilizing the aortic root size and decreasing risk of dissection in Marfan syndrome patients. A bespoke polymer mesh tailored to each patient's individual aorta shape is produced by modeling and then surgically implanted. The aim of this study is to assess the mechanical effects of PEARS on the aortic root systolic downward motion (an important determinant of aortic wall stress), aortic root distension and on the left ventricle (LV). A cohort of 27 Marfan patients had a prophylactic PEARS surgery between 2004 and 2012 with 24 having preoperative and follow-up cardiovascular magnetic resonance imaging studies. Systolic downward aortic root motion, aortic root distension, LV volumes/mass and mitral annular systolic excursion before the operation and in the latest follow-up were measured randomly and blinded. After a median follow-up of 50.5 (IQR 25.5-72) months following implantation of PEARS, systolic downward motion of aortic root was significantly decreased (12.6±3.6mm pre-operation vs 7.9±2.9mm latest follow-up, p<0.00001). There was a tendency for a decrease in systolic aortic root distension but this was not significant (median 4.5% vs 2%, p=0.35). There was no significant change in LV volumes, ejection fraction, mass and mitral annular systolic excursion in follow-up. PEARS surgery decreases systolic downward aortic root motion which is an important determinant of longitudinal aortic wall stress. Aortic wall distension and Windkessel function are not significantly impaired in the follow-up after implantation of the mesh which is also supported by the lack of deterioration of LV volumes or mass. Crown Copyright © 2015. Published by Elsevier Ireland Ltd. All rights reserved.

  5. Aortic annulus eccentricity before and after transcatheter aortic valve implantation: Comparison of balloon-expandable and self-expanding prostheses

    International Nuclear Information System (INIS)

    Schuhbaeck, Annika; Weingartner, Christina; Arnold, Martin; Schmid, Jasmin; Pflederer, Tobias; Marwan, Mohamed; Rixe, Johannes; Nef, Holger; Schneider, Christian; Lell, Michael; Uder, Michael; Ensminger, Stephan; Feyrer, Richard; Weyand, Michael; Achenbach, Stephan

    2015-01-01

    Highlights: • Post-implant geometry of catheter-based aortic valve prostheses is influenced by aortic valve calcification. • Balloon-expandable prostheses are more circular as compared to self-expanding prostheses. • The impact of post-implant geometry on valve function needs to be investigated. - Abstract: Introduction: The geometry of the aortic annulus and implanted transcatheter aortic valve prosthesis might influence valve function. We investigated the influence of valve type and aortic valve calcification on post-implant geometry of catheter-based aortic valve prostheses. Methods: Eighty consecutive patients with severe aortic valve stenosis (mean age 82 ± 6 years) underwent computed tomography before and after TAVI. Aortic annulus diameters were determined. Influence of prosthesis type and degree of aortic valve calcification on post-implant eccentricity were analysed. Results: Aortic annulus eccentricity was reduced in patients after TAVI (0.21 ± 0.06 vs. 0.08 ± 0.06, p < 0.0001). Post-TAVI eccentricity was significantly lower in 65 patients following implantation of a balloon-expandable prosthesis as compared to 15 patients who received a self-expanding prosthesis (0.06 ± 0.05 vs. 0.15 ± 0.07, p < 0.0001), even though the extent of aortic valve calcification was not different. After TAVI, patients with a higher calcium amount retained a significantly higher eccentricity compared to patients with lower amounts of calcium. Conclusions: Patients undergoing TAVI with a balloon-expandable prosthesis show a more circular shape of the implanted prosthesis as compared to patients with a self-expanding prosthesis. Eccentricity of the deployed prosthesis is affected by the extent of aortic valve calcification

  6. Effects of acute dietary nitrate supplementation on aortic blood pressure and aortic augmentation index in young and older adults.

    Science.gov (United States)

    Hughes, William E; Ueda, Kenichi; Treichler, David P; Casey, Darren P

    2016-09-30

    Aging is associated with elevated blood pressure (peripheral and aortic; BP) and aortic augmentation index (AIx) which may contribute to aortic BP. Although inorganic nitrate consumption reduces peripheral BP in both young and older adults, the effects of nitrate consumption on aortic BP and wave reflection in young and older adults is unknown. Therefore, we sought to characterize the effects of nitrate consumption on aortic BP and AIx in young and older adults. Noninvasive aortic pressure waveforms were synthesized from high-fidelity radial pressure waveforms via applanation tonometry before and following (60, 90, 120, 150, and 180 min) consumption of a nitrate-rich beetroot juice in 26 healthy adults (young: 25 ± 4 years, n = 14; older: 64 ± 5 years, n = 12). Aortic BP and indices of aortic wave reflection (AIx and AIx normalized for heart rate; AIx@75bpm) were calculated from the generated aortic pressure waveform. Nitrate consumption increased plasma nitrite in both groups 60-180 min following beetroot consumption (P young and older adults (P age groups. Conversely, indices of aortic wave reflection were reduced only in young adults following nitrate consumption (range of change from baseline over time: AIx@75bpm, -4.3 to -8.8%, P adults. Taken together, our results suggest that acute dietary nitrate supplementation reduces peripheral and aortic BP similarly in young and older adults despite differential effects on aortic AIx between age groups. Copyright © 2016 Elsevier Inc. All rights reserved.

  7. Prototype moving-ring reactor

    International Nuclear Information System (INIS)

    Smith, A.C. Jr.; Ashworth, C.P.; Abreu, K.E.

    1982-01-01

    We have completed a design of the Prototype Moving-Ring Reactor. The fusion fuel is confined in current-carrying rings of magnetically-field-reversed plasma (Compact Toroids). The plasma rings, formed by a coaxial plasma gun, undergo adiabatic magnetic compression to ignition temperature while they are being injected into the reactor's burner section. The cylindrical burner chamber is divided into three burn stations. Separator coils and a slight axial guide field gradient are used to shuttle the ignited toroids rapidly from one burn station to the next, pausing for 1/3 of the total burn time at each station. D-T- 3 He ice pellets refuel the rings at a rate which maintains constant radiated power

  8. Autumn study on storage rings

    CERN Multimedia

    1974-01-01

    The first two weeks of October have seen storage ring people from accelerator Laboratories throughout the world at CERN to study the fundamental problems of very high energy protonproton colliding beam machines.

  9. Minimal Gromov-Witten rings

    International Nuclear Information System (INIS)

    Przyjalkowski, V V

    2008-01-01

    We construct an abstract theory of Gromov-Witten invariants of genus 0 for quantum minimal Fano varieties (a minimal class of varieties which is natural from the quantum cohomological viewpoint). Namely, we consider the minimal Gromov-Witten ring: a commutative algebra whose generators and relations are of the form used in the Gromov-Witten theory of Fano varieties (of unspecified dimension). The Gromov-Witten theory of any quantum minimal variety is a homomorphism from this ring to C. We prove an abstract reconstruction theorem which says that this ring is isomorphic to the free commutative ring generated by 'prime two-pointed invariants'. We also find solutions of the differential equation of type DN for a Fano variety of dimension N in terms of the generating series of one-pointed Gromov-Witten invariants

  10. Cosmic rings from colliding galaxies

    Energy Technology Data Exchange (ETDEWEB)

    Mitton, S

    1976-11-18

    Research on two ring galaxies has led to the proposal of an interaction model to account for the rings. It is envisaged that this class of galaxy is created when a compact galaxy crashes through the disc of a spiral galaxy. The results of a spectroscopic investigation of the galaxy known as the Cartwheel and of another ring galaxy 11 NZ 4 are discussed. The general picture of ring galaxies which emerges from these studies of a massive starry nucleus with a necklace of emitting gas and some spokes and along the spin axis of the wheel a small companion galaxy that is devoid of interstellar gas. An explanation of these properties is considered.

  11. Ring lasers - a brief history

    Science.gov (United States)

    Klein, Tony

    2017-10-01

    Used these days in inertial navigation, ring lasers are also used in recording the tiniest variations in the Earth's spin, as well in detecting earthquakes and even the drift of continents. How did it all begin?

  12. Mechanisms of recurrent aortic regurgitation after aortic valve repair: predictive value of intraoperative transesophageal echocardiography.

    Science.gov (United States)

    le Polain de Waroux, Jean-Benoît; Pouleur, Anne-Catherine; Robert, Annie; Pasquet, Agnès; Gerber, Bernhard L; Noirhomme, Philippe; El Khoury, Gébrine; Vanoverschelde, Jean-Louis J

    2009-08-01

    The aim of the present study was to examine the intraoperative echocardiographic features associated with recurrent severe aortic regurgitation (AR) after an aortic valve repair surgery. Surgical valve repair for AR has significant advantages over valve replacement, but little is known about the predictors and mechanisms of its failure. We blindly reviewed all clinical, pre-operative, intraoperative, and follow-up transesophageal echocardiographic data of 186 consecutive patients who underwent valve repair for AR during a 10-year period and in whom intraoperative and follow-up echo data were available. After a median follow-up duration of 18 months, 41 patients had recurrent 3+ AR, 23 patients presented with residual 1+ to 2+ AR, and 122 had no or trivial AR. In patients with recurrent 3+ AR, the cause of recurrent AR was the rupture of a pericardial patch in 3 patients, a residual cusp prolapse in 26 patients, a restrictive cusp motion in 9 patients, an aortic dissection in 2 patients, and an infective endocarditis in 1 patient. Pre-operatively, all 3 groups were similar for aortic root dimensions and prevalence of bicuspid valve (overall 37%). Patients with recurrent AR were more likely to display Marfan syndrome or type 3 dysfunction pre-operatively. At the opposite end, patients with continent AR repair at follow-up were more likely to have type 2 dysfunction pre-operatively. After cardiopulmonary bypass, a shorter coaptation length, the degree of cusp billowing, a lower level of coaptation (relative to the annulus), a larger diameter of the aortic annulus and the sino-tubular junction, the presence of a residual AR, and the width of its vena contracta were associated with the presence of AR at follow-up. Multivariate Cox analysis identified a shorter coaptation length (odds ratio [OR]: 0.8, p = 0.05), a coaptation occurring below the level of the aortic annulus (OR: 7.9, p < 0.01), a larger aortic annulus (OR: 1.2, p = 0.01), and residual aortic regurgitation

  13. Can early aortic root surgery prevent further aortic dissection in Marfan syndrome?

    OpenAIRE

    Shimizu, Hideyuki; Kasahara, Hirofumi; Nemoto, Atsushi; Yamabe, Kentaro; Ueda, Toshihiko; Yozu, Ryohei

    2011-01-01

    We reviewed 50 patients with Marfan syndrome who underwent surgery for aortic root pathologies comprising a root aneurysm without (n = 25; group A) and with (n = 25; group B) dissection. Aortic root repair included Bentall (n = 37) and valve-sparing (n = 13) procedures. Hospital mortality was 4.0%. Twenty-two patients required 36 repeat surgeries on the distal aorta. The main indication for re-intervention was the dilation of the false lumen. In group A, the distal aorta was stable for up to ...

  14. Over 20 years experience with aortic homograft in aortic valve replacement during acute infective endocarditis.

    Science.gov (United States)

    Solari, Silvia; Mastrobuoni, Stefano; De Kerchove, Laurent; Navarra, Emiliano; Astarci, Parla; Noirhomme, Philippe; Poncelet, Alain; Jashari, Ramadan; Rubay, Jean; El Khoury, Gebrine

    2016-12-01

    Despite the controversy, the aortic homograft is supposedly the best option in acute infective endocarditis (AIE), due to its resistance to reinfection. However, the technical complexity and the risk of structural deterioration over time have limited its utilization. The aim of this study was to evaluate the long-term results of aortic homograft for the treatment of infective endocarditis in our institution with particular attention to predictors of survival and homograft reoperation. The cohort includes 112 patients who underwent aortic valve replacement with an aortic homograft for AIE between January 1990 and December 2014. Fifteen patients (13.4%) died during the first 30 days after the operation. Two patients were lost to follow-up after discharge from the hospital; therefore, 95 patients were available for long-term analysis. The median duration of follow-up was 7.8 years (IQR 4.7-17.6). Five patients (5.3%) suffered a recurrence of infective endocarditis (1 relapse and 4 new episodes). Sixteen patients (16.8%) were reoperated for structural valve degeneration (SVD; n = 14, 87.5%) or for infection recurrence (n = 2, 12.5%). Freedom from homograft reoperation for infective endocarditis or structural homograft degeneration at 10 and 15 years postoperatively was 86.3 ± 5.5 and 47.3 ± 11.0%, respectively. For patients requiring homograft reoperation, the median interval to reintervention was 11.6 years (IQR 8.3-14.5). Long-term survival was 63.6% (95% CI 52.4-72.8%) and 53.8% (95% CI 40.6-65.3%) at 10 and 15 years, respectively. The use of aortic homograft in acute aortic valve endocarditis is associated with a remarkably low risk of relapsing infection and very acceptable long-term survival. The risk of reoperation due to SVD is significant after one decade especially in young patients. The aortic homograft seems to be ideally suited for reconstruction of the aortic valve and cardiac structures damaged by the infective process especially in early surgery.

  15. Ring insertions as light sources

    International Nuclear Information System (INIS)

    Green, G.K.

    1975-01-01

    Bending magnets can be inserted in the long straight sections of electron storage rings to produce synchrotron radiation. If the design is carefully proportioned, the bending magnets create only a small perturbation of the properties of the ring. The resulting spectra have favorable optical properties as sources for spectroscopy and diffraction studies. The characteristics of the source are discussed, and the geometrical requirements of the magnets are presented

  16. Collector ring project at FAIR

    International Nuclear Information System (INIS)

    Dolinskii, A; Blell, U; Dimopoulou, C; Gorda, O; Leibrock, H; Litvinov, S; Laier, U; Schurig, I; Weinrich, U; Berkaev, D; Koop, I; Starostenko, A; Shatunov, P

    2015-01-01

    The collector ring is a dedicated ring for fast cooling of ions coming from separators at the FAIR project. To accommodate optimal technical solutions, a structure of a magnet lattice was recently reviewed and modified. Consequently, more appropriate technical solutions for the main magnets could be adopted. A general layout and design of the present machine is shown. The demanding extraction schemes have been detailed and open design issues were completed. (paper)

  17. Synlig læring

    DEFF Research Database (Denmark)

    Brandsen, Mads

    2017-01-01

    Introduktionen af John Hatties synlig læring i den danske skoleverden møder stadig meget kritik. Mange lærere og pædagoger oplever synlig læring som en tornado, der vil opsuge og ødelægge deres særlige danske udgave af den kontinentale dannelsestænkning, didaktik og pædagogik. Spørgsmålet er om...

  18. The circular RFQ storage ring

    International Nuclear Information System (INIS)

    Ruggiero, A.G.

    1998-01-01

    This paper presents a novel idea of storage ring for the accumulation of intense beams of light and heavy ions at low energy. The new concept is a natural development of the combined features used in a conventional storage ring and an ion trap, and is basically a linear RFQ bend on itself. In summary the advantages are: smaller beam dimensions, higher beam intensity, and a more compact storage device

  19. The Circular RFQ Storage Ring

    International Nuclear Information System (INIS)

    Ruggiero, A. G.

    1999-01-01

    This paper presents a novel idea of storage ring for the accumulation of intense beams of light and heavy ions at low energy. The new concept is a natural development of the combined features of conventional storage rings and ion traps, and is basically a linear RFQ bent on itself. The advantages are: smaller beam dimensions, higher beam intensity, and a more compact storage device

  20. Electrically charged dilatonic black rings

    International Nuclear Information System (INIS)

    Kunduri, Hari K.; Lucietti, James

    2005-01-01

    In this Letter we present (electrically) charged dilatonic black ring solutions of the Einstein-Maxwell-dilaton theory in five dimensions and we consider their physical properties. These solutions are static and as in the neutral case possess a conical singularity. We show how one may remove the conical singularity by application of a Harrison transformation, which physically corresponds to supporting the charged ring with an electric field. Finally, we discuss the slowly rotating case for arbitrary dilaton coupling

  1. Low emittance electron storage rings

    Science.gov (United States)

    Levichev, E. B.

    2018-01-01

    Low-emittance electron (positron) beams are essential for synchrotron light sources, linear collider damping rings, and circular Crab Waist colliders. In this review, the principles and methods of emittance minimization are discussed, prospects for developing relativistic electron storage rings with small beam phase volume are assessed, and problems related to emittance minimization are examined together with their possible solutions. The special features and engineering implementation aspects of various facilities are briefly reviewed.

  2. Resonance capture and Saturn's rings

    International Nuclear Information System (INIS)

    Patterson, C.W.

    1986-05-01

    We have assigned the resonances apparently responsible for the stabilization of the Saturn's shepherd satellites and for the substructure seen in the F-ring and the ringlets in the C-ring. We show that Saturn's narrow ringlets have a substructure determined by three-body resonances with Saturn's ringmoons and the sun. We believe such resonances have important implications to satellite formation. 17 refs., 1 fig., 1 tab

  3. Postoperative Reverse Remodeling and Symptomatic Improvement in Normal-Flow Low-Gradient Aortic Stenosis After Aortic Valve Replacement

    DEFF Research Database (Denmark)

    Carter-Storch, Rasmus; Møller, Jacob E; Christensen, Nicolaj L

    2017-01-01

    BACKGROUND: Severe aortic stenosis (AS) most often presents with reduced aortic valve area (benefit of aortic valve...... replacement (AVR) among NFLG patients is controversial. We compared the impact of NFLG condition on preoperative left ventricular (LV) remodeling and myocardial fibrosis and postoperative remodeling and symptomatic benefit. METHODS AND RESULTS: Eighty-seven consecutive patients with reduced aortic valve area...... and normal stroke volume index undergoing AVR underwent echocardiography, magnetic resonance imaging, a 6-minute walk test, and measurement of natriuretic peptides before and 1 year after AVR. Myocardial fibrosis was assessed from magnetic resonance imaging. Patients were stratified as NFLG or normal...

  4. Early Outcomes of Sutureless Aortic Valves

    Directory of Open Access Journals (Sweden)

    Muhammet Onur Hanedan

    2016-06-01

    Full Text Available Background: In elderly high-risk surgical patients, sutureless aortic valve replacement (AVR should be an alternative to standard AVR. The potential advantages of sutureless aortic prostheses include reducing cross-clamping and cardiopulmonary bypass (CPB time and facilitating minimally invasive surgery and complex cardiac interventions, while maintaining satisfactory hemodynamic outcomes and low rates of paravalvular leakage. The current study reports our single-center experience regarding the early outcomes of sutureless aortic valve implantation. Methods: Between October 2012 and June 2015, 65 patients scheduled for surgical valve replacement with symptomatic aortic valve disease and New York Heart Association function of class II or higher were included to this study. Perceval S (Sorin Biomedica Cardio Srl, Sallugia, Italy and Edwards Intuity (Edwards Lifesciences, Irvine, CA, USA valves were used. Results: The mean age of the patients was 71.15±8.60 years. Forty-four patients (67.7% were female. The average preoperative left ventricular ejection fraction was 56.9±9.93. The CPB time was 96.51±41.27 minutes and the cross-clamping time was 60.85±27.08 minutes. The intubation time was 8.95±4.19 hours, and the intensive care unit and hospital stays were 2.89±1.42 days and 7.86±1.42 days, respectively. The mean quantity of drainage from chest tubes was 407.69±149.28 mL. The hospital mortality rate was 3.1%. A total of five patients (7.69% died during follow-up. The mean follow-up time was 687.24±24.76 days. The one-year survival rate was over 90%. Conclusion: In the last few years, several models of valvular sutureless bioprostheses have been developed. The present study evaluating the single-center early outcomes of sutureless aortic valve implantation presents the results of an innovative surgical technique, finding that it resulted in appropriate hemodynamic conditions with acceptable ischemic time.

  5. Early Outcomes of Sutureless Aortic Valves.

    Science.gov (United States)

    Hanedan, Muhammet Onur; Mataracı, İlker; Yürük, Mehmet Ali; Özer, Tanıl; Sayar, Ufuk; Arslan, Ali Kemal; Ziyrek, Uğur; Yücel, Murat

    2016-06-01

    In elderly high-risk surgical patients, sutureless aortic valve replacement (AVR) should be an alternative to standard AVR. The potential advantages of sutureless aortic prostheses include reducing cross-clamping and cardiopulmonary bypass (CPB) time and facilitating minimally invasive surgery and complex cardiac interventions, while maintaining satisfactory hemodynamic outcomes and low rates of paravalvular leakage. The current study reports our single-center experience regarding the early outcomes of sutureless aortic valve implantation. Between October 2012 and June 2015, 65 patients scheduled for surgical valve replacement with symptomatic aortic valve disease and New York Heart Association function of class II or higher were included to this study. Perceval S (Sorin Biomedica Cardio Srl, Sallugia, Italy) and Edwards Intuity (Edwards Lifesciences, Irvine, CA, USA) valves were used. The mean age of the patients was 71.15±8.60 years. Forty-four patients (67.7%) were female. The average preoperative left ventricular ejection fraction was 56.9±9.93. The CPB time was 96.51±41.27 minutes and the cross-clamping time was 60.85±27.08 minutes. The intubation time was 8.95±4.19 hours, and the intensive care unit and hospital stays were 2.89±1.42 days and 7.86±1.42 days, respectively. The mean quantity of drainage from chest tubes was 407.69±149.28 mL. The hospital mortality rate was 3.1%. A total of five patients (7.69%) died during follow-up. The mean follow-up time was 687.24±24.76 days. The one-year survival rate was over 90%. In the last few years, several models of valvular sutureless bioprostheses have been developed. The present study evaluating the single-center early outcomes of sutureless aortic valve implantation presents the results of an innovative surgical technique, finding that it resulted in appropriate hemodynamic conditions with acceptable ischemic time.

  6. Aortic ruptures in seat belt wearers.

    Science.gov (United States)

    Arajärvi, E; Santavirta, S; Tolonen, J

    1989-09-01

    Several investigations have indicated that rupture of the thoracic aorta is one of the leading causes of immediate death in victims of road traffic accidents. In Finland in 1983, 92% of front-seat passengers were seat belt wearers on highways and 82% in build-up areas. The mechanisms of rupture of the aorta have been intensively investigated, but the relationship between seat belt wearing and injury mechanisms leading to aortic rupture is still largely unknown. This study comprises 4169 fatally injured victims investigated by the Boards of Traffic Accident Investigation of Insurance Companies during the period 1972 to 1985. Chest injuries were recorded as the main cause of death in 1121 (26.9%) victims, 207 (5.0%) of those victims having worn a seat belt. Aortic ruptures were found at autopsy in 98 victims and the exact information of the location of the aortic tears was available in 68. For a control group, we analyzed 72 randomly chosen unbelted victims who had a fatal aortic rupture in similar accidents. The location of the aortic rupture in unbelted victims was more often in the ascending aorta, especially in drivers, whereas in seat belt wearers the distal descending aorta was statistically more often ruptured, especially in right-front passengers (p less than 0.05). The steering wheel predominated statistically as the part of the car estimated to have caused the injury in unbelted victims (37/72), and some interior part of the car was the most common cause of fatal thoracic impacts in seat belt wearers (48/68) (p less than 0.001). The mechanism of rupture of the aorta in the classic site just distal to the subclavian artery seems to be rapid deceleration, although complex body movements are also responsible in side impact collisions. The main mechanism leading to rupture of the ascending aorta seems to be severe blow to the bony thorax. This also often causes associated thoracic injuries, such as heart rupture and sternal fracture. Injuries in the ascending

  7. Energy spectra of quantum rings.

    Science.gov (United States)

    Fuhrer, A; Lüscher, S; Ihn, T; Heinzel, T; Ensslin, K; Wegscheider, W; Bichler, M

    2001-10-25

    Quantum mechanical experiments in ring geometries have long fascinated physicists. Open rings connected to leads, for example, allow the observation of the Aharonov-Bohm effect, one of the best examples of quantum mechanical phase coherence. The phase coherence of electrons travelling through a quantum dot embedded in one arm of an open ring has also been demonstrated. The energy spectra of closed rings have only recently been studied by optical spectroscopy. The prediction that they allow persistent current has been explored in various experiments. Here we report magnetotransport experiments on closed rings in the Coulomb blockade regime. Our experiments show that a microscopic understanding of energy levels, so far limited to few-electron quantum dots, can be extended to a many-electron system. A semiclassical interpretation of our results indicates that electron motion in the rings is governed by regular rather than chaotic motion, an unexplored regime in many-electron quantum dots. This opens a way to experiments where even more complex structures can be investigated at a quantum mechanical level.

  8. Renal Infarction from Type B Aortic Dissection

    Directory of Open Access Journals (Sweden)

    Marit Tweet

    2017-07-01

    Full Text Available History of present illness: A 69-year-old-female with a medical history of hypertension presented to the emergency department (ED complaining of sudden onset of lower back and abdominal pain. Eight hours prior to presentation she reported turning to grab something on another counter and felt a sudden onset sharp pain in her lower back. She began to notice ill-defined abdominal pain, although she denied any shortness of breath, chest pain, numbness, weakness, or urologic symptoms. Her vital signs on presentation to the ED were temperature 36.5˚C, blood pressure 143/88, heart rate 84, respiratory rate 14, and oxygen saturation 93% on room air. On arrival, the patient was in significant discomfort and was rolling on the bed due to pain. Although she appeared to be in moderate distress she had minimal, if any, tenderness on abdominal exam, and only mild left lower back tenderness to palpation. This disconnect between the patient’s apparent discomfort and the lack of physical exam findings prompted the ordering of a computed tomography angiography (CTA of the abdomen/pelvis with greatest suspicion for abdominal aortic aneurysm. Significant findings: Initial abdominal images demonstrated a dissection flap; therefore, a CTA of the chest was also obtained. These images revealed a Stanford type B aortic dissection beginning just distal to the left subclavian artery and extending to the origin of the inferior mesenteric artery. The right renal artery arose from the true lumen of the dissection while the left renal artery arose from the false lumen. This case is interesting as imaging shows the lack of perfusion to the left kidney, residing in the retroperitoneum, which correlates with her non-descript abdominal and left flank pain. Discussion: Aortic dissection is defined as a tear within the wall of the aorta that allows blood to track between intima and media layers. A dissection is classified as Stanford Type A if it involves any portion of the

  9. Outcomes of Aortic Valve-Sparing Operations in Marfan Syndrome.

    Science.gov (United States)

    David, Tirone E; David, Carolyn M; Manlhiot, Cedric; Colman, Jack; Crean, Andrew M; Bradley, Timothy

    2015-09-29

    In many cardiac units, aortic valve-sparing operations have become the preferred surgical procedure to treat aortic root aneurysm in patients with Marfan syndrome, based on relatively short-term outcomes. This study examined the long-term outcomes of aortic valve-sparing operations in patients with Marfan syndrome. All patients with Marfan syndrome operated on for aortic root aneurysm from 1988 through 2012 were followed prospectively for a median of 10 years. Follow-up was 100% complete. Time-to-event analyses were calculated using the Kaplan-Meier method with log-rank test for comparisons. A total of 146 patients with Marfan syndrome had aortic valve-sparing operations. Reimplantation of the aortic valve was performed in 121 and remodeling of the aortic root was performed in 25 patients. Mean age was 35.7 ± 11.4 years and two-thirds were men. Nine patients had acute, 2 had chronic type A, and 3 had chronic type B aortic dissections before surgery. There were 1 operative and 6 late deaths, 5 caused by complications of dissections. Mortality rate at 15 years was 6.8 ± 2.9%, higher than the general population matched for age and sex. Five patients required reoperation on the aortic valve: 2 for endocarditis and 3 for aortic insufficiency. Three patients developed severe, 4 moderate, and 3 mild-to-moderate aortic insufficiency. Rate of aortic insufficiency at 15 years was 7.9 ± 3.3%, lower after reimplantation than remodeling. Nine patients developed new distal aortic dissections during follow-up. Rate of dissection at 15 years was 16.5 ± 3.4%. Aortic valve-sparing operations in patients with Marfan syndrome were associated with low rates of valve-related complications in long-term follow-up. Residual and new aortic dissections were the leading cause of death. Copyright © 2015 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

  10. Improvement of thoracic aortic vasoreactivity by continuous and intermittent exercise in high-fat diet-induced obese rats.

    Science.gov (United States)

    Liu, Hongpeng; Yang, Zhen; Hu, Jian; Luo, Yan; Zhu, Lingqin; Yang, Huifang; Li, Guanghua

    2015-07-01

    The aim of the present study was to explore the effects of continuous and intermittent exercise on the thoracic aortic vasoreactivity and free radical metabolism in rats fed with a high-fat diet (HD). Sprague-Dawley (SD) rats were randomly divided into four groups (n=8, each group): Conventional diet (CD), HD, HD with continuous exercise (HCE) and HD with intermittent exercise (HIE). HCE rats swam once/day for 90 min; HIE rats performed swimming exercises 3 times/day, 30 min each time with an interval of 4 h. In these two groups, the exercise was conducted 5 days a week for 8 weeks. Rats in the CD and HD groups were fed without swimming training. At the end of the exercise, all the rats were sacrificed and the blood, thoracic aorta and myocardium were collected immediately. The thoracic aortic vasoreactivity, the plasma total cholesterol (TC), triglyceride (TG), high-density lipoprotein (HDL), low-density lipoprotein (LDL), superoxide dismutase (SOD), malondialdehyde (MDA) and vascular endothelial nitric oxide synthase (eNOS) gene expression were measured. Compared to the control group, in the HD group the enhanced contractile response of the thoracic aortic rings to noradrenaline (NA) was observed (Pimprove the activity of the thoracic aorta in obese rats, which may be associated with enhanced antioxidant enzyme activity and reduced free radical generating. Additionally, intermittent exercise is better than the continuous exercise in improving the thoracic aorta vasoreactivity.

  11. Asymptomatic strut fracture in DeBakey-Surgitool aortic valves: incidence, management, and metallurgic aspects.

    Science.gov (United States)

    Von Der Emde J, J; Eberlein, U; Breme J, J

    1990-01-01

    From August 1971 through November 1972, we implanted 62 Model 2 DeBakey-Surgitool aortic valve prostheses in 62 patients, 4 of whom later had clinically asymptomatic strut fractures. In 1 case, the patient died suddenly, and autopsy revealed detachment of the ball-cage; in each of the other 3 cases, fractures of 2 struts close to the base of the prosthesis were diagnosed fluoroscopically, and the patients underwent successful reoperation. The interval between implantation and reoperation ranged from 11 months to 16 years, 9 months. In 1 patient, retrospective study of chest radiographs revealed that the fracture had been present for 2(1/2) years. Larger valves (>/= A6) were affected significantly more often than smaller ones. We performed metallurgic analysis of 1 prosthesis: results revealed strut wear from fatigue cracking and secondary abrasion. Strut fracture was also promoted by suspension of the cage at right angles to the prosthetic ring and by use of a pyrolytic carbon ball in a titanium cage (i.e., an occluder harder than its holder). Patients with DeBakey-Surgitool aortic valve prostheses should undergo annual radiologic examinations to enable early detection of strut fractures. Prophylactic valve replacement is not indicated.

  12. Tissue-Engineered Vascular Rings from Human iPSC-Derived Smooth Muscle Cells

    Directory of Open Access Journals (Sweden)

    Biraja C. Dash

    2016-07-01

    Full Text Available There is an urgent need for an efficient approach to obtain a large-scale and renewable source of functional human vascular smooth muscle cells (VSMCs to establish robust, patient-specific tissue model systems for studying the pathogenesis of vascular disease, and for developing novel therapeutic interventions. Here, we have derived a large quantity of highly enriched functional VSMCs from human induced pluripotent stem cells (hiPSC-VSMCs. Furthermore, we have engineered 3D tissue rings from hiPSC-VSMCs using a facile one-step cellular self-assembly approach. The tissue rings are mechanically robust and can be used for vascular tissue engineering and disease modeling of supravalvular aortic stenosis syndrome. Our method may serve as a model system, extendable to study other vascular proliferative diseases for drug screening. Thus, this report describes an exciting platform technology with broad utility for manufacturing cell-based tissues and materials for various biomedical applications.

  13. Accretion in Saturn's F Ring

    Science.gov (United States)

    Meinke, B. K.; Esposito, L. W.; Stewart, G.

    2012-12-01

    Saturn's F ring is the solar system's principal natural laboratory for direct observation of accretion and disruption processes. The ring resides in the Roche zone, where tidal disruption competes with self-gravity, which allows us to observe the lifecycle of moonlets. Just as nearby moons create structure at the B ring edge (Esposito et al. 2012) and the Keeler gap (Murray 2007), the F ring "shepherding" moons Prometheus and Pandora stir up ring material and create observably changing structures on timescales of days to decades. In fact, Beurle et al (2010) show that Prometheus makes it possible for "distended, yet gravitationally coherent clumps" to form in the F ring, and Barbara and Esposito (2002) predicted a population of ~1 km bodies in the ring. In addition to the observations over the last three decades, the Cassini Ultraviolet Imaging Spectrograph (UVIS) has detected 27 statistically significant features in 101 occultations by Saturn's F ring since July 2004. Seventeen of those 27 features are associated with clumps of ring material. Two features are opaque in occultation, which makes them candidates for solid objects, which we refer to as Moonlets. The 15 other features partially block stellar signal for 22 m to just over 3.7 km along the radial expanse of the occultation. Upon visual inspection of the occultation profile, these features resemble Icicles, thus we will refer to them as such here. The density enhancements responsible for such signal attenuations are likely due to transient clumping of material, evidence that aggregations of material are ubiquitous in the F ring. Our lengthy observing campaign reveals that Icicles are likely transient clumps, while Moonlets are possible solid objects. Optical depth is an indicator of clumping because more-densely aggregated material blocks more light; therefore, it is natural to imagine moonlets as later evolutionary stage of icicle, when looser clumps of material compact to form a feature that appears

  14. Double acting stirling engine piston ring

    Science.gov (United States)

    Howarth, Roy B.

    1986-01-01

    A piston ring design for a Stirling engine wherein the contact pressure between the piston and the cylinder is maintained at a uniform level, independent of engine conditions through a balancing of the pressure exerted upon the ring's surface and thereby allowing the contact pressure on the ring to be predetermined through the use of a preloaded expander ring.

  15. Study for ILC Damping Ring at KEKB

    Energy Technology Data Exchange (ETDEWEB)

    Flanagan, J.W.; Fukuma, H.; Kanazawa, K.I.; Koiso, H.; Masuzawa, M.; Ohmi, Kazuhito; Ohnishi, Y.; Oide, Katsunobu; Suetsugu, Y.; Tobiyama, M.; /KEK, Tsukuba; Pivi, M.; /SLAC

    2011-11-04

    ILC damping ring consists of very low emittance electron and positron storage rings. It is necessary for ILC damping ring to study electron cloud effects in such low emittance positron ring. We propose a low emittance operation of KEKB to study the effects.

  16. A new iridoid and effect on the rat aortic vascular smooth muscle cell proliferation of isolated compounds from Buddleja officinalis.

    Science.gov (United States)

    Tai, Bui Huu; Nhiem, Nguyen Xuan; Quang, Tran Hong; Ngan, Nguyen Thi Thanh; Tung, Nguyen Huu; Kim, Yohan; Lee, Jung-Jin; Myung, Chang-Seon; Cuong, Nguyen Manh; Kim, Young Ho

    2011-06-01

    A new iridoid, named methylscutelloside (1) together with 19 known compounds belonging to the iridoids (2-4), monoterpenoids (5), flavonoids (6-8), triterpenoids (9-14), and phenylethanoids (15-20) were isolated from the flowers of Buddleja officinalis. Their chemical structures were elucidated on the basis of physicochemical properties, and by spectroscopic methods including 1D, 2D NMR, and MS. All isolated compounds were tested in vitro for their effects on the proliferation of rat aortic vascular smooth muscle cells (VSMCs). Among them, iridoids were the main active components and showed significant inhibitory effects on PDGF-BB-induced proliferation in rat aortic VSMCs. Copyright © 2011 Elsevier Ltd. All rights reserved.

  17. Fabrication of a compliant phantom of the human aortic arch for use in Particle Image Velocimetry (PIV experimentation

    Directory of Open Access Journals (Sweden)

    Hütter Larissa

    2016-09-01

    Full Text Available Compliant phantoms of the human aortic arch can mimic patient specific cardiovascular dysfunctions in vitro. Hence, phantoms may enable elucidation of haemodynamic disturbances caused by aortic dysfunction. This paper describes the fabrication of a thin-walled silicone phantom of the human ascending aorta and brachiocephalic artery. The model geometry was determined via a meta-analysis and modelled in SolidWorks before 3D printing. The solid model surface was smoothed and scanned with a 3D scanner. An offset outer mould was milled from Ebalta S-Model board. The final phantom indicated that ABS was a suitable material for the internal model, the Ebalta S-Model board yielded a rough external surface. Co-location of the moulds during silicone pour was insufficient to enable consistent wall thickness. The resulting phantom was free of air bubbles but did not have the desired wall thickness consistency.

  18. Possible mechanisms involved in the vasorelaxant effect produced by clobenzorex in aortic segments of rats

    Directory of Open Access Journals (Sweden)

    J. Lozano-Cuenca

    Full Text Available Clobenzorex is a metabolic precursor of amphetamine indicated for the treatment of obesity. Amphetamines have been involved with cardiovascular side effects such as hypertension and pulmonary arterial hypertension. The aim of the present study was to investigate whether the direct application of 10–9–10–5 M clobenzorex on isolated phenylephrine-precontracted rat aortic rings produces vascular effects, and if so, what mechanisms may be involved. Clobenzorex produced an immediate concentration-dependent vasorelaxant effect at the higher concentrations (10–7.5–10–5 M. The present outcome was not modified by 10–6 M atropine (an antagonist of muscarinic acetylcholine receptors, 3.1×10–7 M glibenclamide (an ATP-sensitive K+ channel blocker, 10–3 M 4-aminopyridine (4-AP; a voltage-activated K+ channel blocker, 10–5 M indomethacin (a prostaglandin synthesis inhibitor, 10–5 M clotrimazole (a cytochrome P450 inhibitor or 10–5 M cycloheximide (a general protein synthesis inhibitor. Contrarily, the clobenzorex-induced vasorelaxation was significantly attenuated (P<0.05 by 10–5 M L-NAME (a direct inhibitor of nitric oxide synthase, 10–7 M ODQ (an inhibitor of nitric oxide-sensitive guanylyl cyclase, 10–6 M KT 5823 (an inhibitor of protein kinase G, 10–2 M TEA (a Ca2+-activated K+ channel blocker and non-specific voltage-activated K+ channel blocker and 10–7 M apamin plus 10–7 M charybdotoxin (blockers of small- and large-conductance Ca2+-activated K+ channels, respectively, and was blocked by 8×10–2 M potassium (a high concentration and removal of the vascular endothelium. These results suggest that the direct vasorelaxant effect by clobenzorex on phenylephrine-precontracted rat aortic rings involved stimulation of the NO/cGMP/PKG/Ca2+-activated K+ channel pathway.

  19. A Single Resistance Exercise Session Improves Aortic Endothelial Function in Hypertensive Rats

    Directory of Open Access Journals (Sweden)

    Thaís de Oliveira Faria

    Full Text Available Abstract Background: Physical exercise is an important tool for the improvement of endothelial function. Objective: To assess the effects of acute dynamic resistance exercise on the endothelial function of spontaneously hypertensive rats (SHR. Methods: Ten minutes after exercise, the aorta was removed to evaluate the expression of endothelial nitric oxide synthase (eNOS, phosphorylated endothelial nitric oxide synthase (p-eNOS1177 and inducible nitric oxide synthase (iNOS and to generate concentration-response curves to acetylcholine (ACh and to phenylephrine (PHE. The PHE protocol was also performed with damaged endothelium and before and after NG-nitro-L-arginine methyl ester (L-NAME and indomethacin administration. The maximal response (Emax and the sensitivity (EC50 to these drugs were evaluated. Results: ACh-induced relaxation increased in the aortic rings of exercised (Ex rats (Emax= -80 ± 4.6%, p < 0.05 when compared to those of controls (Ct (Emax = -50 ± 6.8%. The Emax to PHE was decreased following exercise conditions (95 ± 7.9%, p < 0.05 when compared to control conditions (120 ± 4.2%. This response was abolished after L-NAME administration or endothelial damage. In the presence of indomethacin, the aortic rings' reactivity to PHE was decreased in both groups (EC50= Ex -5.9 ± 0.14 vs. Ct -6.6 ± 0.33 log µM, p < 0.05 / Emax = Ex 9.5 ± 2.9 vs. Ct 17 ± 6.2%, p < 0.05. Exercise did not alter the expression of eNOS and iNOS, but increased the level of p-eNOS. Conclusion: A single resistance exercise session improves endothelial function in hypertensive rats. This response seems to be mediated by increased NO production through eNOS activation.

  20. Aortocaval fistula – rare complication of ruptured abdominal aortic ...

    African Journals Online (AJOL)

    in 0.2 - 1.3% of patients with degenerative aortic aneurysms. 1 This paper describes the presentation and successful management of a patient with such an ACF. We wish to highlight the need to maintain a high index of suspicion for this condition in patients with abdominal aortic aneurysms (AAA), particularly if they present ...