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Baylor LR, Commaux N, Jernigan TC, Brooks NH, Combs SK, Evans TE, Fenstermacher ME, Isler RC, Lasnier CJ, Meitner SJ, Moyer RA, Osborne TH, Parks PB, Snyder PB, Strait EJ, Unterberg EA, Loarte A. Reduction of edge-localized mode intensity using high-repetition-rate pellet injection in tokamak H-mode plasmas. Phys Rev Lett 2013; 110:245001. [PMID: 25165932 DOI: 10.1103/physrevlett.110.245001] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2012] [Indexed: 06/03/2023]
Abstract
High repetition rate injection of deuterium pellets from the low-field side (LFS) of the DIII-D tokamak is shown to trigger high-frequency edge-localized modes (ELMs) at up to 12× the low natural ELM frequency in H-mode deuterium plasmas designed to match the ITER baseline configuration in shape, normalized beta, and input power just above the H-mode threshold. The pellet size, velocity, and injection location were chosen to limit penetration to the outer 10% of the plasma. The resulting perturbations to the plasma density and energy confinement time are thus minimal (<10%). The triggered ELMs occur at much lower normalized pedestal pressure than the natural ELMs, suggesting that the pellet injection excites a localized high-n instability. Triggered ELMs produce up to 12× lower energy and particle fluxes to the divertor, and result in a strong decrease in plasma core impurity density. These results show for the first time that shallow, LFS pellet injection can dramatically accelerate the ELM cycle and reduce ELM energy fluxes on plasma facing components, and is a viable technique for real-time control of ELMs in ITER.
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Affiliation(s)
- L R Baylor
- Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-8072, USA
| | - N Commaux
- Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-8072, USA
| | - T C Jernigan
- Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-8072, USA
| | - N H Brooks
- General Atomics, San Diego, California 92186-5608, USA
| | - S K Combs
- Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-8072, USA
| | - T E Evans
- General Atomics, San Diego, California 92186-5608, USA
| | - M E Fenstermacher
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - R C Isler
- Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-8072, USA
| | - C J Lasnier
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - S J Meitner
- Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-8072, USA
| | - R A Moyer
- University of California San Diego, La Jolla, California 92093-0319, USA
| | - T H Osborne
- General Atomics, San Diego, California 92186-5608, USA
| | - P B Parks
- General Atomics, San Diego, California 92186-5608, USA
| | - P B Snyder
- General Atomics, San Diego, California 92186-5608, USA
| | - E J Strait
- General Atomics, San Diego, California 92186-5608, USA
| | - E A Unterberg
- Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-8072, USA
| | - A Loarte
- ITER Organization, Route de Vinon sur Verdon, 13115 Saint Paul Lez Durance Cedex, France
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Magee RM, Galante ME, McCarren D, Scime EE, Boivin RL, Brooks NH, Groebner RJ, Hill DN, Porter GD. A two photon absorption laser induced fluorescence diagnostic for fusion plasmas. Rev Sci Instrum 2012; 83:10D701. [PMID: 23126875 DOI: 10.1063/1.4728092] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
The quality of plasma produced in a magnetic confinement fusion device is influenced to a large extent by the neutral gas surrounding the plasma. The plasma is fueled by the ionization of neutrals, and charge exchange interactions between edge neutrals and plasma ions are a sink of energy and momentum. Here we describe a diagnostic capable of measuring the spatial distribution of neutral gas in a magnetically confined fusion plasma. A high intensity (5 MW/cm(2)), narrow bandwidth (0.1 cm(-1)) laser is injected into a hydrogen plasma to excite the Lyman β transition via the simultaneous absorption of two 205 nm photons. The absorption rate, determined by measurement of subsequent Balmer α emission, is proportional to the number of particles with a given velocity. Calibration is performed in situ by filling the chamber to a known pressure of neutral krypton and exciting a transition close in wavelength to that used in hydrogen. We present details of the calibration procedure, including a technique for identifying saturation broadening, measurements of the neutral density profile in a hydrogen helicon plasma, and discuss the application of the diagnostic to plasmas in the DIII-D tokamak.
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Affiliation(s)
- R M Magee
- Physics Department, West Virginia University, Morgantown, 26506, USA.
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3
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Howard J, Diallo A, Creese M, Blackwell BD, Allen SL, Ellis RM, Porter GD, Meyer W, Fenstermacher ME, Brooks NH, Van Zeeland ME, Boivin RL. Doppler coherence imaging and tomography of flows in tokamak plasmas (invited). Rev Sci Instrum 2010; 81:10E528. [PMID: 21034056 DOI: 10.1063/1.3492422] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
This article describes the results of spatial heterodyne Doppler "coherence imaging" of carbon ion flows in the divertor region of the DIII-D tokamak. Spatially encoded interferometric projections of doubly ionized carbon emission at 465 nm have been demodulated and tomographically inverted to obtain the spatial distribution of the carbon ion parallel flow and emissivity. The operating principles of the new instruments are described, and the link between measured properties and line integrals of the flow field are established. An iterative simultaneous arithmetic reconstruction procedure is applied to invert the interferometric phase shift projections, and the reconstructed parallel flow field amplitudes are found to be in reasonable agreement with UEDGE modeling.
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Affiliation(s)
- J Howard
- Plasma Research Laboratory, The Australian National University, Canberra 0200, Australia.
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4
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Brooks NH, Burrell KH, Isler RC, Meyer O, Pablant NA. Charge exchange recombination detection of low-Z and medium-Z impurities in the extreme UV using a digital lock-in technique. Rev Sci Instrum 2010; 81:10D721. [PMID: 21033914 DOI: 10.1063/1.3478691] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
More sensitive detection of charge exchange recombination lines from low-Z elements, and first-time detection from the medium-Z elements nickel and copper, has been achieved in DIII-D plasmas with a digital lock-in technique. That portion of the extreme UV spectrum varying synchronously in time with the square-wave modulation of a high energy, neutral heating beam is extracted by forming a scalar product of a correlation function with the data record of each pixel in the linear array detector. The usual, dense array of collisionally excited, metallic lines from the tokamak plasma is strongly suppressed, leaving only a sparse spectrum of lines dominated by charge exchange recombination transitions from fully stripped, low-Z elements. In plasmas with high metal content, charge exchange recombination lines from the Li-like ions of nickel and copper have been positively identified.
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Affiliation(s)
- N H Brooks
- General Atomics, P.O. Box 85608, San Diego, California 92186-5608, USA.
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5
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Schmitz O, Evans TE, Fenstermacher ME, Unterberg EA, Austin ME, Bray BD, Brooks NH, Frerichs H, Groth M, Jakubowski MW, Lasnier CJ, Lehnen M, Leonard AW, Mordijck S, Moyer RA, Osborne TH, Reiter D, Samm U, Schaffer MJ, Unterberg B, West WP. Resonant pedestal pressure reduction induced by a thermal transport enhancement due to stochastic magnetic boundary layers in high temperature plasmas. Phys Rev Lett 2009; 103:165005. [PMID: 19905705 DOI: 10.1103/physrevlett.103.165005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2009] [Indexed: 05/28/2023]
Abstract
Good alignment of the magnetic field line pitch angle with the mode structure of an external resonant magnetic perturbation (RMP) field is shown to induce modulation of the pedestal electron pressure p(e) in high confinement high rotation plasmas at the DIII-D tokamak with a shape similar to ITER, the next step tokamak experiment. This is caused by an edge safety factor q95 resonant enhancement of the thermal transport, while in contrast, the RMP induced particle pump out does not show a significant resonance. The measured p(e) reduction correlates to an increase in the modeled stochastic layer width during pitch angle variations matching results from resistive low rotation plasmas at the TEXTOR tokamak. These findings suggest a field line pitch angle resonant formation of a stochastic magnetic edge layer as an explanation for the q95 resonant character of type-I edge localized mode suppression by RMPs.
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Affiliation(s)
- O Schmitz
- Forschungszentrum Jülich GmbH, IEF4-Plasma Physics, 52428 Jülich, Germany
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McLean AG, Davis JW, Stangeby PC, Brooks NH, Ellis RM, Haasz AA, Rudakov DL, West WP, Whyte DG, Wong CPC. Porous plug gas injection systems for studies of hydrocarbon dissociation and transport in the DIII-D tokamak. Rev Sci Instrum 2009; 80:043501. [PMID: 19405654 DOI: 10.1063/1.3100180] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
A probe has been designed, constructed, and successfully used to inject methane into the DIII-D lower divertor in a manner imitating natural release by chemical erosion. This porous plug injector (PPI) probe consists of a self-contained gas reservoir with an integrated pressure gauge and a 3 cm diameter porous surface through which gas is injected into the lower divertor of the tokamak. The probe is positioned flush with the divertor target surface by means of the divertor materials evaluation system. Two gas delivery systems were developed: in the first, gas flow is regulated by a remotely controlled microvalve and in the second by a fixed micro-orifice flow restrictor. Because of the large area of the porous surface through which gas is admitted, the injected hydrocarbon molecules see a local carbon surface (>90% carbon) similar to that seen by hydrocarbons being emitted by chemical sputtering from surrounding carbon tiles. The distributed gas source also reduces the disturbance to the local plasma while providing sufficient signal for spectroscopic detection. In situ spectroscopic measurements with the PPI in DIII-D allow the direct calibration of response for measured plasma conditions from a known influx of gas.
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Affiliation(s)
- A G McLean
- Institute for Aerospace Studies, University of Toronto, 4925 Dufferin St., Toronto, Ontario M3H 5T6, Canada.
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Groth M, Ellis RM, Brooks NH, Fenstermacher ME, Lasnier CJ, Meyer WH, Moeller JM. Measurements of spatial line emission profiles in the main scrape-off layer of the DIII-D tokamak. Rev Sci Instrum 2009; 80:033505. [PMID: 19334920 DOI: 10.1063/1.3103575] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
A video camera system is described as that measures the spatial distribution of visible line emission emitted from the main scrape-off layer (SOL) of plasmas in the DIII-D tokamak. A wide-angle lens installed on an equatorial port and an in-vessel mirror, which intercepts part of the lens' view, provide simultaneous tangential views of the SOL on the low-field and high-field sides of the plasma's equatorial plane. Tomographic reconstruction techniques are used to calculate the two-dimensional (2D) poloidal profiles from the raw data, and one-dimensional (1D) poloidal profiles simulating chordal views of other optical diagnostics from the 2D profiles. The 2D profiles can be compared with SOL plasma simulations; the 1D profiles with measurements from spectroscopic diagnostics. Sample results are presented, which elucidate carbon transport in plasmas with toroidally uniform injection of methane and argon transport in disruption mitigation experiments with massive gas jet injection.
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Affiliation(s)
- M Groth
- Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California, 94551-0808, USA
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8
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Brooks NH, Colchin RJ, Fehling DT, Hillis DL, Mu Y, Unterberg E. Filterscopes: spectral line monitors for long-pulse plasma devices. Rev Sci Instrum 2008; 79:10F330. [PMID: 19044638 DOI: 10.1063/1.2957777] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
A photomultiplier (PMT)-based diagnostic system for monitoring spectral lines along multiple viewchords, named the "Filterscope" [R. J. Colchin et al., Rev. Sci. Instrum. 74, 2068 (2003)], is currently in use at the DIII-D, NSTX, and CDX-U fusion plasma devices in the US, and has been installed at the KSTAR device in Korea. This diagnostic has recently been upgraded for application to long-pulse devices, such as KSTAR, EAST in China, and the future ITER in France. A new data acquisition system, employing the PXI instrumentation platform with an embedded Windows microprocessor controller, can simultaneously record up to 72 channels at 100 kHz sampling rates for plasma periods lasting up to 20 min. Based on the average signal level during an adjustable time interval (100 ms in the present DIII-D implementation), the controller digitally adjusts PMT dynode voltage throughout the course of a discharge, thereby maintaining the output signals at a level where they are neither saturated nor dominated by digitizer noise. The new system's ability to accommodate large variations in source strength, discharge to discharge and within a single discharge, has proved particularly valuable during DIII-D operations, since changes between top, bottom, and double-null divertor magnetic configurations lead to large temporal variations in signal brightness.
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Affiliation(s)
- N H Brooks
- General Atomics, P.O. Box 85608, San Diego, California 92186-5608, USA
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Rudakov DL, Yu JH, Boedo JA, Hollmann EM, Krasheninnikov SI, Moyer RA, Muller SH, Pigarov AY, Rosenberg M, Smirnov RD, West WP, Boivin RL, Bray BD, Brooks NH, Hyatt AW, Wong CPC, Roquemore AL, Skinner CH, Solomon WM, Ratynskaia S, Fenstermacher ME, Groth M, Lasnier CJ, McLean AG, Stangeby PC. Dust measurements in tokamaks (invited). Rev Sci Instrum 2008; 79:10F303. [PMID: 19044616 DOI: 10.1063/1.2969422] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Dust production and accumulation present potential safety and operational issues for the ITER. Dust diagnostics can be divided into two groups: diagnostics of dust on surfaces and diagnostics of dust in plasma. Diagnostics from both groups are employed in contemporary tokamaks; new diagnostics suitable for ITER are also being developed and tested. Dust accumulation in ITER is likely to occur in hidden areas, e.g., between tiles and under divertor baffles. A novel electrostatic dust detector for monitoring dust in these regions has been developed and tested at PPPL. In the DIII-D tokamak dust diagnostics include Mie scattering from Nd:YAG lasers, visible imaging, and spectroscopy. Laser scattering is able to resolve particles between 0.16 and 1.6 microm in diameter; using these data the total dust content in the edge plasmas and trends in the dust production rates within this size range have been established. Individual dust particles are observed by visible imaging using fast framing cameras, detecting dust particles of a few microns in diameter and larger. Dust velocities and trajectories can be determined in two-dimension with a single camera or three-dimension using multiple cameras, but determination of particle size is challenging. In order to calibrate diagnostics and benchmark dust dynamics modeling, precharacterized carbon dust has been injected into the lower divertor of DIII-D. Injected dust is seen by cameras, and spectroscopic diagnostics observe an increase in carbon line (CI, CII, C(2) dimer) and thermal continuum emissions from the injected dust. The latter observation can be used in the design of novel dust survey diagnostics.
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Affiliation(s)
- D L Rudakov
- University of California, San Diego, California 92093, USA
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Walter M, Bureau JF, Holmes BM, Bertha EA, Hollander M, Wheelis J, Brooks NH, Lyons-Ruth K. Cortisol response to interpersonal stress in young adults with borderline personality disorder: a pilot study. Eur Psychiatry 2008; 23:201-204. [PMID: 18325742 PMCID: PMC2585780 DOI: 10.1016/j.curpsy.2007.12.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/18/2007] [Revised: 12/28/2007] [Accepted: 12/30/2007] [Indexed: 06/02/2023] Open
Abstract
Hypothalamic-pituitary-adrenal axis dysregulation after stress was found to be associated with borderline personality disorder (BPD). Nine female BPD young adults and 12 control subjects were investigated for stress reactivity and recovery after an interpersonal conflict discussion with their mothers. BPD subjects showed a delayed cortisol response after psychosocial stress.
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Affiliation(s)
- Marc Walter
- Department of Psychiatry, University of Basel, Wilhelm Klein-Strasse 27, CH-4025 Basel, Switzerland.
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Walter M, Bureau JF, Holmes BM, Bertha EA, Hollander M, Wheelis J, Brooks NH, Lyons-Ruth K. Cortisol response to interpersonal stress in young adults with borderline personality disorder: a pilot study. Eur Psychiatry 2008; 23:201-4. [PMID: 18325742 PMCID: PMC2585780 DOI: 10.1016/j.eurpsy.2007.12.003] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/18/2007] [Revised: 12/28/2007] [Accepted: 12/30/2007] [Indexed: 10/22/2022] Open
Abstract
Hypothalamic-pituitary-adrenal axis dysregulation after stress was found to be associated with borderline personality disorder (BPD). Nine female BPD young adults and 12 control subjects were investigated for stress reactivity and recovery after an interpersonal conflict discussion with their mothers. BPD subjects showed a delayed cortisol response after psychosocial stress.
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Affiliation(s)
- Marc Walter
- Department of Psychiatry, University of Basel, Wilhelm Klein-Strasse 27, CH-4025 Basel, Switzerland.
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12
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Khan W, Deepak SM, Coppinger T, Waywell C, Borg A, Harper L, Williams SG, Brooks NH. Beta blocker treatment is associated with improvement in renal function and anaemia in patients with heart failure. Heart 2006; 92:1856-7. [PMID: 17105890 PMCID: PMC1861276 DOI: 10.1136/hrt.2005.083998] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
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Kumar S, Suresh V, Prendergast BD, Brooks NH, Wicks P, Levy RD, Ray SG, Bennett DH, Lee HS. Outcome in the real-world of coronary high-risk intervention with drug-eluting stents (ORCHID)—A single-center study comparing Cypher™ sirolimus-eluting with Taxus™ paclitaxel-eluting stents. Catheter Cardiovasc Interv 2006; 68:663-8. [PMID: 17034063 DOI: 10.1002/ccd.20741] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
OBJECTIVE We present real world experience from a single center registry comparing the 6-month outcome of percutaneous coronary intervention (PCI) in unselected high-risk individuals using either sirolimus-eluting (SES) or paclitaxel-eluting stents (PES). METHODS/RESULTS We compared clinical outcome at 6 months follow-up in two cohorts of 156 consecutive patients (total n = 312) who underwent SES (June 2002-February 2003) and PES (march 2003-July 2003) implantation. The primary endpoint was a composite of major adverse cardiac events (MACE). Baseline clinical characteristics were well matched. The 6-month target vessel revascularization (TVR) rates were 1.9% (SES) and 2.6% (PES) and MACE rates were similar in the two groups (SES 4.5% vs. PES 3.2%, P = NS). In the PES group, intervention for multivessel disease, bifurcation lesions and in small vessels was more common, and for in-stent restenosis less common, reflecting the impact of drug eluting stents on indications for PCI. The incidence of sub-acute stent thrombosis, related to inadequate antiplatelet therapy in 3 of the 6 cases, was 0.95% with no difference between the two groups. CONCLUSION This study confirms the safety and efficacy of SES and PES in unselected high risk patients undergoing PCI. Clinical outcomes of both stents are equivalent at 6 months with low rates of MACE and TVR. These data provide important complementary information to forthcoming randomized studies.
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Affiliation(s)
- S Kumar
- Department of Cardiology, Wythenshawe Hospital, Manchester M23 9LT, United Kingdom.
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Densem CG, Mutlak ASM, Pravica V, Brooks NH, Yonan N, Hutchinson IV. A novel polymorphism of the gene encoding furin, a TGF-β1 activator, and the influence on cardiac allograft vasculopathy formation. Transpl Immunol 2004; 13:185-90. [PMID: 15381201 DOI: 10.1016/j.trim.2004.04.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2003] [Revised: 04/07/2004] [Accepted: 04/16/2004] [Indexed: 11/28/2022]
Abstract
BACKGROUND Coronary vasculopathy (CV) is an important determinant of survival following cardiac transplantation. We have previously shown that G915C polymorphism of the Transforming Growth Factor-beta1 (TGF-beta1) gene strongly influences CV development. Furin is a proprotein convertase enzyme important in TGF-beta1 activation. We investigated for polymorphism within the promoter region of the gene for furin (fur). Allelic variation of the fur gene, in conjunction with TGF-beta1 polymorphism, was subsequently related to the development of CV. METHODS AND RESULTS The fur gene promoter region (position -1199 to +39) was analysed by SSCP and sequencing. A C/T single nucleotide substitution polymorphism at position -231* was identified. Using PCR the fur and TGFB1 genotypes were identified in 115 cardiac transplant recipients. CV was diagnosed at routine surveillance post-transplant coronary angiography. Fur polymorphism had no influence on vasculopathy development; median time to diagnosis, *C/C homozygotes, 2.27 years (2.10-4.32), *C/T heterozygotes 2.97 years (2.09-4.24), *T/T homozygotes 2.65 years (2.33-4.08), (P=0.95). Allelic variation did not influence Kaplan Meier actuarial analysis of disease onset (P=0.54). Ninety-three percent of recipients were high TGF-beta1 producers. We used fur polymorphism to substratify patients with the +915*G/G TGFB1 (high producing) allele. Fur polymorphism did not influence CV development within this TGF-beta1 high producer cohort, when analysed by time to first diagnosis and Kaplan Meier testing. CONCLUSIONS We have described a novel polymorphism at position -231* in the gene encoding furin. The fur -231* single nucleotide polymorphism in isolation, or in conjunction with TGFB1 polymorphism, is not useful as a genetic risk marker for cardiac transplant associated coronary vasculopathy.
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Affiliation(s)
- C G Densem
- Cardiothoracic Transplant Unit, Wythenshawe Hospital, Manchester, UK.
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Densem CG, Hutchinson IV, Yonan N, Brooks NH. Donor and recipient-transforming growth factor-beta 1 polymorphism and cardiac transplant-related coronary artery disease. Transpl Immunol 2004; 13:211-7. [PMID: 15381204 DOI: 10.1016/j.trim.2004.06.005] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2004] [Revised: 06/27/2004] [Accepted: 06/28/2004] [Indexed: 10/26/2022]
Abstract
BACKGROUND Transforming growth factor-beta1 (TGF-beta1) has been implicated in the pathogenesis of coronary vasculopathy following cardiac transplantation. The TGFB1 gene contains polymorphisms at positions +915* (Arg25Pro) and +869* (Leu10Pro) which may influence TGF-beta1 expression. We investigated the relationship between the development of coronary vasculopathy and the prevalence of these alleles in a cardiac transplant population. METHODS Vasculopathy was diagnosed at routine surveillance post-transplant coronary angiography. Using sequence-specific polymerase chain reaction we identified the TGFB1 +915* and +869* genotypes in 147 cardiac transplant recipients and 134 cardiac donors. RESULTS TGFB1 +915*C allele carriers (low producers) made up 10.5% of the recipient population but were significantly less likely to develop coronary vasculopathy (P=0.03). Median time to diagnosis was 6.0 years (3.9-8.72) in +915*C allele carriers compared to 2.75 years (2.10-4.22) in *G/G homozygotes (p=0.002). Pre- and 1 year post-transplant clinical variables were equivalent between the two groups. Multivariate analysis identified the recipient +915*G/G genotype (hazard ratio 2.96 (95% CI, 1.09-9.98); p=0.039), donor age (hazard ratio 1.05 (95% CI, 1.02-1.09); p=0.008) and number of acute rejection episodes of ISHLT grade 3 or greater in the first year (hazard ratio 1.12 (95% CI, 1.01-1.23); p=0.03) as significant predictors of vasculopathy. The recipient TGFB1 +869*, and both alleles in the donor, had no influence on vasculopathy development. CONCLUSIONS Recipient TGFB1 +915* genotype influences the development of cardiac transplant-related coronary vasculopathy. This gives an important insight to the pathophysiology of the disease. On the contrary, donor TGFB1 +915* and TGFB1 +869* polymorphisms do not appear to be important and cannot be used as genetic risk factors.
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Affiliation(s)
- C G Densem
- Cardiothoracic Transplant Unit, Wythenshawe Hospital, Manchester, UK.
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Abstract
A 61 year old patient was found to have an aneurysm extending from the aortic root to the suprarenal region. He underwent first stage surgery with aortic root and arch replacement, prosthetic aortic valve replacement, and coronary artery bypass grafting. Four weeks later, he presented with breathlessness and signs of heart failure and pleural effusion. Computed tomography showed that the left atrium was compressed between the aortic aneurysm posteriorly and the left ventricle and sternum anteriorly. Obstruction of the superior vena cava, bronchus, oesophagus, and rarely right atrium by an aortic aneurysm has been described before but presentation with left atrial compression has not been reported.
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Affiliation(s)
- N M Gandhi
- Regional Cardiothoracic Centre, Wythenshawe Hospital, Manchester, UK.
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18
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Densem CG, Hutchinson IV, Yonan N, Brooks NH. Influence of interleukin-10 polymorphism on the development of coronary vasculopathy following cardiac transplantation. Transpl Immunol 2003; 11:223-8. [PMID: 12799207 DOI: 10.1016/s0966-3274(03)00015-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Interleukin-10 (IL-10), an important anti-inflammatory cytokine has been implicated in the pathogenesis of acute rejection and long term graft tolerance. Polymorphism in the IL-10 promoter at positions -1082, -819 and -592, correlates with IL-10 production. Haplotype inheritance of these alleles determines whether individuals are high, intermediate, or low producers of IL-10. We investigated the effect of this polymorphism on the development of cardiac transplant vasculopathy (CV). METHODS CV was defined at routine surveillance coronary angiography as any abnormality in 1 or more epicardial vessels. Recipient and donor DNA was amplified by PCR using primers to the 3 allele sites. After identifying the phenotype by electrophoresis, freedom from CV was analysed by Kaplan-Meier and the log rank test. RESULTS One hundred and forty eight recipients and 135 donors were studied. High, intermediate and low producers made up 26.4, 47.3 and 26.3% of recipients and 35.6, 48.2 and 16.2% of donors (P=0.42). No significant differences were noted between the phenotype groups. The recipient and donor genotypes, when considered in isolation, had no effect on the freedom from CV; recipients: P=0.85; donors: P=0.52. When the recipient and donor genotypes were combined for an individual patient the freedom from CV was again unaffected; high producing IL-10 allele in donor or recipient: P=0.76, low producing IL-10 allele in donor or recipient: P=0.51. Increasing donor age and acute rejection episodes and the presence of a high producing TGF-beta1 phenotype were independent risk factors for CV. CONCLUSIONS Polymorphism of the IL-10 promoter region fails to predict the development of CV and cannot be used as a genetic risk marker. This may be due to the effects of immunosuppressive treatment.
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Affiliation(s)
- C G Densem
- Cardiothoracic Transplant Unit, Wythenshawe Hospital, Manchester, UK
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Colchin RJ, Schaffer MJ, Carreras BA, McKee GR, Maingi R, Carlstrom TN, Rudakov DL, Greenfield CM, Rhodes TL, Doyle EJ, Brooks NH, Austin ME. Slow L-H transitions in DIII-D plasmas. Phys Rev Lett 2002; 88:255002. [PMID: 12097092 DOI: 10.1103/physrevlett.88.255002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/24/2001] [Indexed: 05/23/2023]
Abstract
The transition from the low to the high mode of plasma confinement ( L-H transition) is studied in the DIII-D by an experimental technique which allows an arbitrarily slow transition. During an initial transition, periodic turbulent instability bursts are observed near the separatrix which inhibit the full transition. These bursts are damped by self-generated shear flows, and a predator-prey-type relationship is shown to give a good description of the data. As the neutral-beam power is raised, the oscillations change to type III edge localized modes. Another transition then leads to a quiet H mode.
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Affiliation(s)
- R J Colchin
- Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-8072, USA
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Abstract
BACKGROUND Tumour necrosis factor alpha (TNF alpha) is implicated in the pathophysiology of heart failure. Plasma TNF alpha is raised in patients with myocardial dysfunction in proportion to the symptoms. OBJECTIVE To determine whether this genetic variant is over represented in heart transplant recipients. PATIENTS 175 heart transplant recipients and a control group of 212 healthy volunteers were studied. The reason for transplantation was severe symptomatic myocardial dysfunction in all cases. METHODS The TNF alpha genotype was determined by polymerase chain reaction and gel electrophoresis. The populations were compared for their fit to Hardy-Weinberg equilibrium by calculating the expected frequencies of each genotype and comparing them to the observed values. A chi(2) test was used to determine the significance of the difference between the observed and expected values. RESULTS No differences were found in the frequency of the TNF2 allele between all heart transplant recipients taken together (54/175, 31%) and healthy volunteers (58/212, 27%). A higher proportion of TNF2 allele carriers was present in cardiac recipients with a pretransplant diagnosis of viral mediated or idiopathic heart failure than in those with ischaemic myocardial dysfunction (26/69 (37.7%) v 28/106 (26.4%), p = 0.03). PATIENTS with a non-ischaemic aetiology had a higher prevalence of TNF2 than healthy volunteers (26/69 (37.7%) v 58/212 (27%), p = 0.05). CONCLUSIONS The TNF2 allele is overrepresented in patients with end stage non-ischaemic myocardial dysfunction. This may represent a genetic predisposition in a small subset of patients who could respond favourably to anti-TNF alpha treatment.
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Affiliation(s)
- C G Densem
- Cardiothoracic Transplant Unit, Wythenshawe Hospital, Manchester, UK School of Biological Sciences, Manchester University, UK
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21
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Densem CG, Hutchinson IV, Yonan N, Brooks NH. Influence of tumor necrosis factor-alpha gene-308 polymorphism on the development of coronary vasculopathy after cardiac transplantation. J Heart Lung Transplant 2001; 20:1265-73. [PMID: 11744409 DOI: 10.1016/s1053-2498(01)00358-8] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND Tumor necrosis factor-alpha (TNF-alpha) has been implicated in cardiovascular disease. Polymorphism of the TNF-alpha gene promoter region (position -308) influences an individual's production of TNF-alpha. This affects susceptibility to acute rejection after cardiac transplantation. Because the highest serum levels of TNF-alpha have been found in recipients with cardiac transplant vasculopathy and because TNF-alpha blockade can prevent the disease in rabbits, we investigated the effect of TNF-alpha promoter polymorphism on the development of vasculopathy in human cardiac allograft recipients. METHODS Using sequence-specific primers to the TNF-alpha gene and polymerase chain reaction, the genotypes of 147 cardiac transplant recipients and 134 heart donors were identified. An association was sought between the presence of high-producing (A homozygotes, GA heterozygotes) or low-producing (G homozygotes) TNF-alpha genotype and the development of coronary vasculopathy, diagnosed by routine surveillance coronary angiography. RESULTS We found that 31.9% of recipients and 27.0% of donors were high TNF-alpha producers. The presence of the high-producing TNF-alpha allele led to an earlier diagnosis of vasculopathy; 3.42 years (+/- 91.3 days) vs 3.84 years (+/- 76.3 days) for high- and low-producing cardiac graft recipients, respectively; 3.52 years (+/- 87.3 days) vs 3.78 years (+/- 77.4 days) for high- and low-producing donor grafts, respectively. However, neither of these differences were significant. By Kaplan Meier actuarial analysis and log-rank test, TNF-alpha polymorphism had no effect on the freedom from vasculopathy when considering either recipient (p = 0.99) or donor (p = 0.86) TNF-alpha genotype. Multivariate analysis identified increasing donor age and the number of acute rejection episodes of International Society for Heart and Lung Transplantation grade 3 or greater as independent risk factors for vasculopathy in both the recipient and donor cohorts. CONCLUSIONS Polymorphism at position -308 in the promoter region of the TNF-alpha gene fails to predict the development of cardiac transplant-related vasculopathy and cannot be used as a genetic risk marker. This may be because of the effects of immunosuppressive treatment.
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Affiliation(s)
- C G Densem
- Cardiothoracic Transplant Unit, Wythenshawe Hospital, United Kingdom, Manchester, UK
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Abstract
Aspirin is a widely used drug and perceived by most physicians to be inexpensive. High rates of concurrent gastroprotective agents are reported from a study of cardiology outpatients. Aspirin takers are more likely to also be taking a proton pump inhibitor, H(2) antagonist, or antacid than non-aspirin takers. They are more than 10 times as likely to be experiencing upper gastrointestinal symptoms. Although aspirin is inexpensive, it is emphasised that the overall cost implications for therapy can be significant and it is suggested that it may be more appropriate to consider the use of alternative antiplatelet agents in patients who tolerate aspirin poorly.
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Affiliation(s)
- M I Burgess
- Department of Cardiology, Wythenshawe Hospital, Southmoor Road, Manchester M23 9LT, UK.
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Densem CG, Hutchinson IV, Cooper A, Yonan N, Brooks NH. Polymorphism of the transforming growth factor-beta 1 gene correlates with the development of coronary vasculopathy following cardiac transplantation. J Heart Lung Transplant 2000; 19:551-6. [PMID: 10867335 DOI: 10.1016/s1053-2498(00)00114-5] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
BACKGROUND Expression of transforming growth factor-beta1 (TGF-beta1) is central to vascular repair due to its effects on smooth muscle cell, monocyte/macrophage, leucocyte, and extracellular matrix accumulation and proliferation. Genetic polymorphism at position +915 of the TGF-beta1 gene determines the degree of cytokine production in response to injury. We investigated this allelic variation on the development of cardiac transplant-related coronary vasculopathy (CV). METHODS Using sequence-specific primers to the TGF-beta1 gene region of interest, a polymerase chain reaction (PCR) and gel electrophoresis identified the genotype in 129 cardiac transplant recipients. An association was sought between the presence of a high- (GG) or low/intermediate-producing (CC/GC) genotype and the development of coronary vasculopathy diagnosed by coronary angiography. RESULTS C allele carriers made up 10.9% of the recipient population but were significantly less likely to develop coronary vasculopathy (p = 0. 0361). Mean time to diagnosis was 1240.5 days in G homozygotes relative to 2266.5 days in C allele carriers (p = 0.002). Pre- and 1-year posttransplant clinical variables were equivalent between the 2 groups. Multivariate analysis identified the GG genotype (p = 0. 042, hazard ratio 3.01, [95% CI, 1.056-10.99]), donor age (p = 0.002, hazard ratio 1.063, [95% CI, 1.029-1.097]), and number of acute-rejection episodes of grade 3 or greater in the first year (p = 0.029, hazard ratio 1.11, [95% CI, 1.05-1.26]) as significant predictors of vasculopathy. CONCLUSION This study demonstrates a correlation between a high-producing TGF-beta1 genotype and an earlier onset of cardiac-transplant coronary vasculopathy. This gives an important insight into the pathophysiology of cardiac transplant vasculopathy and suggests new treatment options.
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Affiliation(s)
- C G Densem
- Cardiothoracic Transplant Unit, Wythenshawe Hospital, Manchester, UK
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24
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Burgess MI, Aziz TM, Ray SG, Yonan N, Brooks NH. Value of echocardiography in predicting long term outcome after heart transplantation. Heart 2000; 83:105-6. [PMID: 10671075 PMCID: PMC1729277 DOI: 10.1136/heart.83.1.103d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
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Densem CG, Hutchinson IV, Yonan N, Brooks NH. TGF-beta gene polymorphism does not influence the rise in creatinine following cardiac transplantation. Transpl Immunol 1999; 7:247-9. [PMID: 10638838 DOI: 10.1016/s0966-3274(99)80009-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
- C G Densem
- Department of Cardiology, Wythenshawe University Hospital, Manchester, UK
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26
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Ryan TJ, Antman EM, Brooks NH, Califf RM, Hillis LD, Hiratzka LF, Rapaport E, Riegel B, Russell RO, Smith EE, Weaver WD, Gibbons RJ, Alpert JS, Eagle KA, Gardner TJ, Garson A, Gregoratos G, Ryan TJ, Smith SC. 1999 update: ACC/AHA guidelines for the management of patients with acute myocardial infarction. A report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Committee on Management of Acute Myocardial Infarction). J Am Coll Cardiol 1999; 34:890-911. [PMID: 10483976 DOI: 10.1016/s0735-1097(99)00351-4] [Citation(s) in RCA: 545] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Ryan TJ, Antman EM, Brooks NH, Califf RM, Hillis LD, Hiratzka LF, Rapaport E, Riegel B, Russell RO, Smith EE, Weaver WD, Gibbons RJ, Alpert JS, Eagle KA, Gardner TJ, Garson A, Gregoratos G, Smith SC. 1999 update: ACC/AHA Guidelines for the Management of Patients With Acute Myocardial Infarction: Executive Summary and Recommendations: A report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Committee on Management of Acute Myocardial Infarction). Circulation 1999; 100:1016-30. [PMID: 10468535 DOI: 10.1161/01.cir.100.9.1016] [Citation(s) in RCA: 454] [Impact Index Per Article: 18.2] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Abstract
OBJECTIVE To compare patient selection and outcome of coronary angioplasty procedures before and after the widespread availability and use of stents. SUBJECTS AND METHODS Group 1 consisted of 252 consecutive patients and group 2 comprised 389 patients who underwent angioplasty between April 1993 and March 1994, and April 1995 and March 1996, respectively, in a tertiary cardiothoracic centre. Clinical variables were collected before the procedures. Endpoints included in-hospital death, the need for repeat coronary angiography, repeat angioplasty, and coronary artery bypass surgery. Lesions were classified under American Heart Association/American College of Cardiology criteria in 100 randomly selected patients from each group. RESULTS 311 and 482 angioplasty procedures were performed in patients from groups 1 and 2, respectively. One or more stents were deployed in nine (4%) and 179 (46%, p < 0.01) patients, respectively. The success rate was higher in group 2 than in group 1 patients (483/523 (92%) v 274/372 (88%), respectively, p < 0.05). There were significantly more single vessel angioplasty procedures (198/252 (79%) v 272/389 (70%), p < 0.05), type A lesions (30/116 (26%) v 19/130 (15%), p < 0.05), patients with stable angina (220/252 (87%) v 311/389 (80%), p < 0.05), and fewer acute myocardial infarction patients (1/252 (0%) v 12/389 (3%), p < 0.05) treated in group 1 than in group 2, respectively. Similar numbers of angioplasty were performed in the left anterior descending, left circumflex, and right coronary arteries. There were no significant differences in the in-hospital mortality or the need for repeat coronary angiography, angioplasty, or bypass surgery at 24 hours or six months after the initial procedure. CONCLUSION Patients undergoing angioplasty in the stenting era had features associated with an increased risk of complication. Despite this, the primary success rate was higher, and the complication rate and the need for subsequent revascularisation were similar in the two groups, supporting the widely held clinical impression that stenting has made a valuable impact on the practice of angioplasty.
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Affiliation(s)
- H S Lee
- Department of Cardiology, Wythenshawe Hospital, Manchester, UK
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Millane T, Hearing SD, Jones PE, Brooks NH. Two ECGs and a history: a guide to early hospital discharge of patients with 'chest pain? cause'. J R Coll Physicians Lond 1998; 32:122-4. [PMID: 9597626 PMCID: PMC9663004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
OBJECTIVES To shorten the stay in hospital of patients admitted with chest pain of uncertain origin, using clinical history and an unchanging ECG as a basis to inform patients on the post-take ward round of imminent discharge that same day (pending normal cardiac enzyme results), thereby facilitating actual discharge on the same day. DESIGN A prospective observational study over a two-month period of consecutive patients admitted with chest pain of uncertain origin. SETTING District general hospital in North-West England with a regional cardiothoracic centre on site. RESULTS Of the 115 patients enrolled in the study (15% of acute medical admissions), 43 (37%) were identified by the investigators as likely to have normal cardiac enzymes and only one of them had evidence of important cardiac ischaemia (median actual length of stay, 3 days). The specificity of the protocol was 98%, with a sensitivity of 89%. CONCLUSIONS A careful clinical history taken by experienced junior staff together with two sequential ECGs, can identify patients who may be discharged within 24 hours of admission with chest pain of uncertain origin. Significant bed savings would result from the instigation of this practice, with minimal requirement for extra resources.
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Affiliation(s)
- T Millane
- Department of Cardiology, Wythenshawe Hospital, Manchester
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Ryan TJ, Anderson JL, Antman EM, Braniff BA, Brooks NH, Califf RM, Hillis LD, Hiratzka LF, Rapaport E, Riegel BJ, Russell RO, Smith EE, Weaver WD. ACC/AHA guidelines for the management of patients with acute myocardial infarction. A report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Committee on Management of Acute Myocardial Infarction). J Am Coll Cardiol 1996; 28:1328-428. [PMID: 8890834 DOI: 10.1016/s0735-1097(96)00392-0] [Citation(s) in RCA: 640] [Impact Index Per Article: 22.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Affiliation(s)
- T J Ryan
- American College of Cardiology, Educational Services, Bethesda, MD 20814-1699, USA
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Ryan TJ, Anderson JL, Antman EM, Braniff BA, Brooks NH, Califf RM, Hillis LD, Hiratzka LF, Rapaport E, Riegel BJ, Russell RO, Smith EE, Weaver WD. ACC/AHA guidelines for the management of patients with acute myocardial infarction: executive summary. A report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Committee on Management of Acute Myocardial Infarction). Circulation 1996; 94:2341-50. [PMID: 8901709 DOI: 10.1161/01.cir.94.9.2341] [Citation(s) in RCA: 207] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
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Grant SC, Guy SP, Lamb WR, Brooks NH, Brenchley PE, Hutchinson IV. Expression of cytokine messenger RNA after heart transplantation: relationship with rejection and serum cytokines. Transplantation 1996; 62:910-6. [PMID: 8878383 DOI: 10.1097/00007890-199610150-00007] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Different groups of cytokines may initiate or inhibit the rejection process. We used the polymerase chain reaction to study the expression of cytokine mRNA for interleukin (IL)-2, -4, -6 and -10, tumor necrosis factor-alpha, and interferon-gamma in 187 biopsy specimens from 24 human cardiac transplant recipients 5-555 days after transplantation. Cytokine levels in the serum were also measured. Cytokine mRNA was detected in 38.5% of biopsy specimens. IL-10 mRNA was detected more frequently with mild or absent rejection (11.6% in grades 0 and 1 - vs. 1.4% in grades 2 and 3, P=0.01). Up to 90 days after transplantation, IL-2 mRNA was detected more frequently with moderate rejection (13% in grades 2 and 3 vs. 0% in grades 0 and 1, P=0.076), and IL-4 mRNA was detected more frequently with mild or absent rejection (16% in grades 0 and 1 - vs. 0% in grades 2 and 3, P=0.061). More than 90 days after transplantation, IL-2 mRNA was detected more frequently with mild or absent rejection (10% in grades 0 and 1 vs. 0% in grades 2 and 3, P=0.078). Serum IL-4 levels corresponding to biopsy specimens positive for IL-4 mRNA were higher than those corresponding to specimens negative for IL-4 mRNA (59 pg/ml vs. 32 pg/ml medians, P=0.028). Our results suggest that IL-10 and possibly IL-4 (T helper 2 cytokines) may suppress graft rejection, whereas IL-2 (T helper 1 cytokine) may promote cellular rejection. In addition, cytokine profiles may change with length of time after transplantation. The association of elevated serum levels of IL-4 with increased expression of intragraft IL-4 mRNA may suggest release of this cytokine from the graft into the circulation.
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Affiliation(s)
- S C Grant
- Department of Cardiology, Transplant Unit, Wythenshawe Hospital, Manchester, England
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Abstract
Cytokines are important in the pathogenesis of allograft rejection. Some studies have suggested a positive relationship between serum levels of cytokines and rejection, so this study was designed to investigate the presence of a range of cytokines in a large cohort of cardiac transplant recipients. We used enzyme linked immunosorbent assays (ELISA) to examine sequential serum samples from 28 consecutive heart transplant recipients; length of follow up varied between 2 and 566 days (median 357 days). Serum levels of IL-2, 4, 6, 10, TNF-alpha, and IFN-gamma were measured. We compared these results with detailed data on patients' clinical courses, including histological rejection, infection, and therapeutic use of antithymocyte globulin (ATG). No significant relationship was found between rejection and serum cytokine levels for samples taken more than 30 days after transplantation. Prior to this cytokine levels were significantly disturbed by the use of cytolytic therapy for induction immunosuppression. Serum cytokine levels sometimes showed peaks that appeared to be related to rejection, or occasionally to infection, but these relationships were not consistent. Serum TNF-alpha and IL-6 were consistently elevated within a few days of administration of ATG. We conclude that there is no systematic relationship between serum cytokine levels and histological rejection or infection in cardiac transplant recipients.
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Affiliation(s)
- S C Grant
- Transplant Unit, Wythenshawe Hospital, Manchester, United Kingdom
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Grant SC, Khan MA, Faragher EB, Yonan N, Brooks NH. Atrial arrhythmias and pacing after orthotopic heart transplantation: bicaval versus standard atrial anastomosis. Heart 1995; 74:149-53. [PMID: 7546993 PMCID: PMC483990 DOI: 10.1136/hrt.74.2.149] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
BACKGROUND Right and left atrial configuration is more normal when the donor left atrium is anastomosed to a recipient left atrial cuff with direct anastomoses of the donor and recipient vena cavas on the right side. The right atrium and sinus node may be less disturbed by the technique of bicaval anastomosis than by the standard procedure. OBJECTIVE To compare the incidence of atrial arrhythmias and pacing after bicaval and standard anastomoses. METHODS 75 patients had heart transplants between January 1991 and December 1993. The notes were reviewed. Nine patients who died within the first 30 days were excluded from further analysis (seven patients with standard anastomoses, one with bicaval anastomosis, and one with a hybrid technique). RESULTS 66 patients survived for more than 30 days. Thirty five patients had standard anastomoses and 31 bicaval anastomoses. Atrial tachyarrhythmias (atrial fibrillation, atrial flutter, atrial tachycardia, or supraventricular tachycardia) occurred on four days in three patients in the bicaval group compared with 27 days in 13 patients in the standard group (P = 0.009). The relative risk of atrial tachyarrhythmias with standard anastomosis was 5.52 (P = 0.015) compared with that of bicaval anastomosis. Atrial tachyarrhythmias requiring treatment occurred less often in the bicaval group (four episodes in three patients in the bicaval group and eight episodes in four patients in the standard group), and fewer patients with a bicaval anastomosis required temporary pacing (pacing on 20 days in 10 patients in the bicaval group, but pacing on 49 days in 16 patients in the standard group) and late permanent pacing (no patients in the bicaval group and three patients in the standard group), although these differences were not statistically significant. Patients in the bicaval group were discharged from hospital sooner than those in the standard group (mean 24.1 v 29.1 days, P = 0.024). CONCLUSIONS The technique of bicaval anastomosis, in addition to theoretical advantages from maintaining a more normal atrial configuration, has a lower incidence of postoperative atrial tachyarrhythmias, may reduce the need for pacing, and allows earlier discharge from hospital.
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Affiliation(s)
- S C Grant
- Department of Cardiology, Wythenshawe Hospital, Manchester
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Wade MR, Hillis DL, Hogan JT, Mahdavi MA, Maingi R, West WP, Brooks NH, Burrell KH, Groebner RJ, Jackson GL, Klepper CC, Laughon G, Menon MM, Mioduszewski PK. Helium Exhaust Studies in H-Mode Discharges in the DIII-D Tokamak Using an Argon-Frosted Divertor Cryopump. Phys Rev Lett 1995; 74:2702-2705. [PMID: 10057996 DOI: 10.1103/physrevlett.74.2702] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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Konstam MA, Dracup K, Baker DW, Bottorff MB, Brooks NH, Dacey RA, Dunbar SB, Jackson AB, Jessup M, Johnson JC. Heart failure: evaluation and care of patients with left ventricular systolic dysfunction. J Card Fail 1995; 1:183-7. [PMID: 9420649 DOI: 10.1016/1071-9164(95)90021-7] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Affiliation(s)
- M A Konstam
- U.S. Department of Health and Human Services, Agency for Health Care Policy and Research, Washington, DC, USA
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Abstract
Two patients died following heart transplantation from failure of the donor right ventricle. Histological examination of the lungs showed occlusion of pulmonary veins. A more reliable method is required to predict the outcome for potential heart transplant recipients with a "borderline" pulmonary vascular resistance.
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Affiliation(s)
- P S Hasleton
- Department of Pathology, Wythenshawe Hospital, Manchester, UK
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41
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Abstract
OBJECTIVE This article reviews the role of counseling, education, dietary modifications, and exercise for patients with heart failure due to left ventricular systolic dysfunction. DATA SOURCE We reviewed studies published in English between 1966 and 1993 and referenced in MEDLINE or EMBASE. We used the search terms heart failure, congestive; congestive heart failure; heart failure; cardiac failure; and dilated cardiomyopathy in conjunction with terms for the specific areas of interest. Where data were lacking, we relied on opinions of panel members and peer reviewers. STUDY SELECTION AND DATA SYNTHESIS: Studies were reviewed to determine whether patients had heart failure due to systolic dysfunction (left ventricular ejection fraction, < 0.35 to 0.40) and whether clinical outcomes were reported. Studies that reported only intermediate outcomes (eg, hemodynamics) were not reviewed. CONCLUSION Counseling and education can improve patient outcomes and decrease unnecessary hospitalizations. Patients with mild to moderate heart failure should be restricted to 3 g/d of sodium initially. Those who are unresponsive to this dosage or who have more severe disease should be advised to consume 2 g/d or less. Patients should be strongly advised to drink no more than 30 mL/d of alcohol or, preferably, to abstain completely. Exercise training is safe and can improve exercise duration and symptoms. Adherence to the treatment plan should be stressed and monitored at each visit. Clinicians should inform patients of the seriousness of their disease and their prognosis, but they should emphasize that patients can continue to remain active and enjoy a reasonable quality of life.
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Affiliation(s)
- K Dracup
- UCLA School of Nursing 90024-6918
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Sheldon S, Hasleton PS, Yonan NA, Rhaman AN, Deiraniya AK, Campbell CS, Brooks NH, Dyer PA. Rejection in heart transplantation strongly correlates with HLA-DR antigen mismatch. Transplantation 1994; 58:719-22. [PMID: 7940693] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
It is well established that incompatible HLA antigens presented by donor tissue readily evoke an immune response. Prospective HLA matching policies, widespread in European kidney transplant centers have reduced the level of HLA mismatching and have significantly improved graft survival. The influence of HLA incompatibility in heart transplantation remains controversial, and prospective HLA matching is seldom achieved. We examined the role of HLA antigen mismatching on transplant rejection by analyzing 2569 endomyocardial biopsies (EMB) from 157 consecutive orthotopic heart transplants performed from April 1987 to August 1993 in our own center. Biopsies were graded according to the accepted International Classification, with grade 2 and higher indicating rejection. Among 91 patients who received a 2 HLA-DR mismatch transplant 34% of 1624 biopsies analyzed were graded as > or = 2. This frequency fell to 29% of 797 biopsies for 53 patients with a one-HLA-DR mismatch and to 18% of 148 biopsies for 13 patients in the zero-HLA-DR-mismatch group (P < 0.00005). No significant effect on EMB grade frequencies was observed using the same method of analysis with transplants mismatched at the HLA-A or HLA-B loci apart from analysis of HLA-B matched transplants at 3 months posttransplant (P = 0.02). The close linkage of the HLA-B and HLA-DR loci may account for this observation. The results of this study show that heart transplants matched at the HLA-DR locus have a significantly reduced incidence of EMB grades indicative of rejection requiring augmented immunosuppressive therapy. We propose that prospective HLA-DR matching should be adopted for allocation of donor hearts for more efficient use of this precious and limited resource.
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Affiliation(s)
- S Sheldon
- North Western Regional Tissue Typing Laboratory, St. Mary's Hospital, Manchester, United Kingdom
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Brooks NH. Five points from the AHCPR guideline on heart failure. Am Fam Physician 1994; 50:531-2. [PMID: 8067317] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
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Abstract
Three cases of Wegener's granulomatosis with cardiac complications are described and the relevant published reports are reviewed. The first case of Wegener's granulomatosis was associated with aortic regurgitation and required aortic valve replacement. The second and third cases were associated with pericardial disease requiring pericardiectomy for constructive pericarditis in one case, and haemorrhagic pericarditis with pericardial effusion in the other. Aortic valve involvement in Wegener's granulomatosis is uncommon and valve replacement has been described on only one previous occasion. Pericardial involvement is relatively common pathologically, but pericardial surgery has been described in this condition only twice, once for tamponade and once for constrictive pericarditis after pericardiocentesis. Cardiac involvement is not uncommon in patients with Wegner's granulomatosis and may be clinically important. Diagnosis is aided by estimation of the anti-neutophil cytoplasmic antibody titre.
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Affiliation(s)
- S C Grant
- Department of Cardiology, Wythenshawe Hospital, Manchester
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Abstract
BACKGROUND The aetiology of idiopathic dilated cardiomyopathy is believed to have an immunological component. Association with human leucocyte antigens (HLAs) has been previously reported, particularly with HLA-DR4. AIM To determine the association of HLA type with diagnosis in a group of patients assessed for heart transplantation. METHODS A comparison was made of frequencies of HLA types in patients with a diagnosis of idiopathic dilated cardiomyopathy or (n = 98) ischaemic heart disease (n = 170) and in controls from the North Western region (n = 857). RESULTS Neither the patients with idiopathic dilated cardiomyopathy nor those with ischaemic heart disease showed a significant increase or decrease in any HLA frequency compared with the controls. CONCLUSION These results suggest that there is no HLA association with idiopathic dilated cardiomyopathy or ischaemic heart disease. This conflicts with the results of some previous studies.
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Affiliation(s)
- S C Grant
- Department of Cardiology, Wythenshawe Hospital, Manchester
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Abstract
The objective of this study was to assess the changes in outcome of cardiac arrest due to ventricular fibrillation, asystole and electromechanical dissociation in relation to the changing guidelines for drug therapy set by the U.K. Resuscitation Council. It was a retrospective study of 667 resuscitation records for the years 1982, 1986, 1988, 1989, 1990 and 1991. It took place in a large district general hospital with a regional cardio-thoracic centre. We have audited the asystolic cardiac arrests (N = 271) which occurred outside the cardiac care unit (CCU). Adrenaline (intravenous 1 mg) is now the first line drug followed by atropine at an increased dose (2 mg intravenously); calcium is no longer recommended and sodium bicarbonate should be reserved for cases in which an acidosis has been documented. Atropine use has increased over the 9-year period. Bicarbonate use did not change from 1982 to 1986 but fell progressively to no use at all in 1991. Calcium use has declined since 1982. Adrenaline use has remained unchanged. Survival from asystolic arrests (hospital discharge) has remained unchanged at 0-5.5%. Asystole as a primary event in the CCU was uncommon (N = 17) and no patient was discharged. Over the same period, 60% of patients (N = 92) with a cardiac arrest on CCU due to ventricular fibrillation (VF) were discharged and 55% were alive after 6 months. For VF on the wards (N = 192), only 20% of patients were discharged from hospital. A similar proportion was successful for each year.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- R D Levy
- Regional Cardiothoracic Unit, Wythenshawe Hospital, Manchester, U.K
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Abstract
BACKGROUND Raised pulmonary vascular resistance is associated with decreased survival after orthotopic heart transplantation and patients with this risk factor are usually denied transplantation. In a proportion of cases raised pulmonary vascular resistance may fall with time and medical treatment. METHODS Seven patients with high pulmonary vascular resistance (range 3.9-6.6 Wood units) at initial assessment for cardiac transplantation were restudied by right heart catheterisation after a period of seven to 17 months. RESULTS In five of the seven patients the pulmonary vascular resistance had fallen, allowing orthotopic heart transplantation to be performed in four. In one patient the resistance was static and in one it had risen. The mean fall in pulmonary vascular resistance for the group was (mean (SD)) 2.6 (2.7) Wood units, p < 0.05. CONCLUSION Patients who have been denied transplantation on the basis of their raised pulmonary vascular resistance should be reassessed after four to six months if they remain otherwise clinically suitable.
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Affiliation(s)
- S C Grant
- Department of Cardiology, Wythenshawe Hospital, Manchester
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Abstract
A woman with advanced coronary artery disease underwent heart transplantation. The donor heart had left ventricular hypertrophy. The electrocardiographic and echocardiographic evidence, of left ventricular hypertrophy regressed during follow up; estimated left ventricular mass decreased from 393 g to 171 g. The adaptation of myocardial mass and performance after transplantation is not fully understood. This case illustrates the potential for regression of left ventricular hypertrophy in response to altered loading conditions.
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Affiliation(s)
- S C Grant
- Department of Cardiology, Wythenshawe Hospital, Manchester
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