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Jeffrey T Cope MD Michael C Mauney MD David Banks BS Oliver A.R Binns MD Christopher L Moore BS Jeffrey J Rentz BS Kimberly S Shockey MS R.Christoper King MD Irving L Kron MD Curtis G Tribble MD 《The Annals of thoracic surgery》1997,63(6)
Background. Hypoxia and warm ischemia produce severe injury to cardiac grafts harvested from non–heart-beating donors. To potentially improve recovery of such grafts, we studied the effects of intravenous phenylephrine preconditioning.Methods. Thirty-seven blood-perfused rabbit hearts were studied. Three groups of non–heart-beating donors underwent intravenous treatment with phenylephrine at 12.5 (n = 8), 25 (n = 7), or 50 μg/kg (n = 7) before initiation of apnea. Non–heart-beating controls (n = 8) received saline vehicle. Hypoxic cardiac arrest occurred after 6 to 12 minutes of apnea, followed by 20 minutes of warm in vivo ischemia. A 45-minute period of ex vivo reperfusion ensued. Nonischemic controls (n = 7) were perfused without antecedent hypoxia or ischemia.Results. Phenylephrine 25 μg/kg significantly delayed the onset of hypoxic cardiac arrest compared with saline controls (9.6 ± 0.5 versus 7.7 ± 0.4 minutes; p = 0.00001), yet improved recovery of left ventricular developed pressure compared with saline controls (57.1 ± 5.3 versus 41.0 ± 3.4 mm Hg; p = 0.04). Phenylephrine 25 μg/kg also yielded a trend toward less myocardial edema than saline vehicle (p = 0.09).Conclusions. Functional recovery of nonbeating cardiac grafts is improved by preconditioning. We provide evidence that the myocardium can be preconditioned with phenylephrine against hypoxic cardiac arrest.(Ann Thorac Surg 1997;63:1664–8) 相似文献
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髁突形态与覆深度关系的研究 总被引:1,自引:0,他引:1
目的 探讨髁突形态与不同覆深度的关系。方法 选择正常者、开畸形患者、覆正常的错畸形患者和深覆畸形患者各 5 0人 ,均为 18至 2 6岁成人。应用曲面断层片研究左右两侧的髁突形态 ,分别测量并计算上部髁突高度 /升支高度比 (UCH/RH)和髁突高度 /宽度比 (TCH/CW )。将髁突形态分为四种类型 :直立型 (类A) ,前倾型 (类B) ,后倾型 (类C)和尖型 (类D)。结果 开组的上部髁突高度相对升支高度明显小于其他各组 (P <0 0 0 1)。正常组的髁突形态比较粗壮 ,高度宽度比明显小于其他各组 (P <0 0 0 1)。类A和类B属于正常髁突形态 ,占正常组的 99%。类C和类D属于异常髁突形态 ,且在开组中的比例明显高于正常覆组或深覆组。另外 ,只有开组中显示上部髁突高度两侧不对称 (P <0 0 5 )。结论 开组髁突形态与其他各组相比明显不同。 相似文献
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Noninvasive metabolic magnetic resonance (MR) imaging reflecting glucose metabolism in the aldose-reductase-sorbitol (ARS) pathway was performed in the rabbit head; after administration of the fluorinated glucose analogue 3-fluoro-3-deoxy-D-glucose (3FD-glucose), fluorine-19 images were generated. Images of 3FD-glucose showed significant 3FD-glucose uptake by adipose tissue, indicating its buffering effects in case of excess loads of glucose. Images of 3-fluoro-3-deoxy-D-sorbitol (3FD-sorbitol) demonstrated the spatial distribution of aldose reductase activities and significant sorbitol accumulation in the lens. Images of 3-fluoro-3-deoxy-D-fructose (3FD-fructose) showed preferential uptake of fructose by muscle tissue. The extremely low toxicity of 3FD-glucose indicates promise for its clinical application in metabolic imaging. 相似文献
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Zusammenfassung Die Sedimentationsraten der kompletten löslichen Hämagglutinine der Adenoviren wurden bei 16 Prototypen der Untergruppe II im Saccharose-Gradienten bestimmt. Die Werte waren für alle Viren ähnlich (65±10S). Dies bedeutet, daß die strukturellen Komponenten ebenfalls identisch sein dürften, also Dodecon (1).
Durchgeführt mit Unterstützung der Deutschen Forschungsgemeinschaft. 相似文献
Dodecon, the soluble hemagglutinin present in all adenovirus types of subgroup II
Summary The sedimentation rate of the soluble complete hemagglutinins of 16 prototype adenoviruses of subgroup II were determined by means of sucrose gradient centrifugation. The rates were similar for all types (65±10S), thus indicating that the structural components may also be identicali.e. dodecon (1).
Durchgeführt mit Unterstützung der Deutschen Forschungsgemeinschaft. 相似文献
6.
Radioactive sources in close contact offer an alternative to superficial radiation in the treatment of skin lesions. A flattening filter was designed for a lead surface applicator to improve the skin dose distribution of a high dose rate (HDR) brachytherapy unit (Nucletron). At three heights from the opening (10, 15 and 25 mm) of the cylindrical applicator, the 192Ir source can be driven into the centre of the applicator. Thin sheets of lead foil (0.2 mm) were cut into circular shapes and placed in the opening to build a cylindrical cone that acts as a flattening filter. The shape of the cone was optimized in an iterative process using a spreadsheet and the resulting dose distribution under the applicator was determined using radiosensitive film. The use of the filter improved the dose distribution in a plane perpendicular to the beam axis to be within +/- 5% of the central axis dose. The present applicator and flattening filter together with an HDR brachytherapy unit offer an alternative for skin irradiation where a superficial unit is not available or will be replaced with a more flexible device. As the depth dose characteristics can be modified using different source-to-surface distances, the dose throughout the patient's skin can be shaped as desired by the radiation oncologist using a compensator design type approach. 相似文献
7.
M A Kron D M Shlaes C Currie-McCumber A A Medeiros 《Antimicrobial agents and chemotherapy》1987,31(12):2007-2009
A total of 31 plasmids, all bearing a gene that encodes a novel, plasmid-mediated Richmond-Sykes class III beta-lactamase designated OHIO-1 and a gene that encodes aminoglycoside 2"-adenyltransferase, have been collected from hospitals in Ohio. By using restriction endonuclease digestion and Southern hybridization, we were able to demonstrate that all these plasmids have a common genetic origin. 相似文献
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Howlett S Kron T Ku NX Hamilton C 《Australasian physical & engineering sciences in medicine / supported by the Australasian College of Physical Scientists in Medicine and the Australasian Association of Physical Sciences in Medicine》1999,22(4):163-165
The aim of this work was to assess the monitor unit calculation accuracy of a new 3D computer planning system in a volume containing significant lung heterogeneity. An anthropomorphic phantom drilled to accommodate a cylindrical ionisation chamber was used for measurements. Results were also compared to an older 2D system and a manual calculation method. Only a slight improvement was achieved with the new system and an energy dependence was evident. This type of test is recommended before implementing a new 3D planning system. 相似文献
10.
Kron IL 《The Annals of thoracic surgery》1999,68(5):1971-1973
Myocardial protection for surgical procedures on the failing heart can be broken down into three areas. The first area involves selection of the appropriate patient with enough myocardial viability and contractile reserve to permit a substantial cross-clamp time. Secondly, there should be adequate targets to revascularize or adequate tissue for reparative surgery. Thirdly, and most importantly, antegrade and retrograde blood cardioplegia given in sufficient amounts to satisfy myocardial oxygen needs is of prime importance. 相似文献