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81.
目的 探讨局部应用抗氧化剂VitC、VitE对准分子激光屈光性角膜切削术(PRK)术后角膜组织的影响。方法 将24只实验免分成2组,每组12只,行双眼一5.0DPRK。一组术后左眼每日结膜下注射VitC0.1g,右眼为对照;另一组术后左眼每日结膜下注射VitE25mg,有眼为对照。于术后1、3、7、14天测定角膜组织超氧化物歧酶(super—oxide dismutase,SOD)、丙二醛(malondialdehyde,MDA)及谷肮甘肽过氧化物酶(glutathioneperoxNe,GSH—PX)的变化,观察其病理变化。结果 术后1、3天角膜SOD、GSH—Px活性小于对照组(P<0.01),MDA的水平高于对照组(P<0.01)。局部应用抗氧化剂组其角膜SOD、GSH—PX活性高于单纯激光组(P<0.01),MDA水平低于单纯激光组(P<0.01)。结论 准分子激光屈光性角膜切削术后,存在着氧自由基性的组织损伤破坏,局部应用VitC、VitE能降低角膜的自由基损伤。 相似文献
82.
Multicoil Dixon chemical species separation with an iterative least-squares estimation method. 总被引:1,自引:0,他引:1
Scott B Reeder Zhifei Wen Huanzhou Yu Angel R Pineda Garry E Gold Michael Markl Norbert J Pelc 《Magnetic resonance in medicine》2004,51(1):35-45
This work describes a new approach to multipoint Dixon fat-water separation that is amenable to pulse sequences that require short echo time (TE) increments, such as steady-state free precession (SSFP) and fast spin-echo (FSE) imaging. Using an iterative linear least-squares method that decomposes water and fat images from source images acquired at short TE increments, images with a high signal-to-noise ratio (SNR) and uniform separation of water and fat are obtained. This algorithm extends to multicoil reconstruction with minimal additional complexity. Examples of single- and multicoil fat-water decompositions are shown from source images acquired at both 1.5T and 3.0T. Examples in the knee, ankle, pelvis, abdomen, and heart are shown, using FSE, SSFP, and spoiled gradient-echo (SPGR) pulse sequences. The algorithm was applied to systems with multiple chemical species, and an example of water-fat-silicone separation is shown. An analysis of the noise performance of this method is described, and methods to improve noise performance through multicoil acquisition and field map smoothing are discussed. 相似文献
83.
G. Kostopanagiotou A. Pandazi I. Andreadou A. Doufas I. Chondroudaki T. Kotsis D. Rizos C. Costopanagiotou V. Smyrniotis 《European journal of vascular and endovascular surgery》2005,30(6):648-653
OBJECTIVE: We investigated the dose-related effect of dopexamine and dopamine on free radical production and lipid peroxidation estimated by MDA measurements in an ischaemia-reperfusion model of supraceliac aortic repair. DESIGN: Prospective, randomized, blinded experimental study. MATERIALS: Twenty-five healthy pigs. METHODS: All experiments were performed under general endotracheal anaesthesia. Supraceliac aortic cross clamping was performed in all pigs. The pigs were randomly assigned into five groups (n=5 in each group) and received a continuous intravenous infusion of normal saline (CTL), dopamine 2 microg kg(-1)min(-1) (dopa 2), dopamine 8 microg kg(-1)min(-1) (dopa 8), dopexamine 2 microg kg(-1)min(-1) (dopex 2), dopexamine 8 microg kg(-1)min(-1) (dopex 8). Cardiac output, mean arterial pressure, arterial blood gas analysis and blood sampling for plasma MDA measurements (to reveal lipid peroxidation) were recorded after induction of anaesthesia (baseline), 60 and 120 min after cross-clamping of aorta (ischaemia phase), and 60 and 120 min after restoration of flow (reperfusion phase). RESULTS: Dopexamine and dopamine at 8 microgkg(-1)min(-1) reduced MDA at 60 and 120 min after reperfusion. CONCLUSION: Dopexamine seems superior to dopamine in reducing oxygen free radicals and subsequent lipid peroxidation during reperfusion after supraceliac aortic cross clamping in pigs. 相似文献
84.
Dr. Joseph A. Kuhn MD Lawrence D. Wagman MD John A. Lorant MD Fredrick W. Grannis MD Mordecai Dunst MD William R. Dougherty MD Daniel I. Jacobs MD 《Annals of surgical oncology》1994,1(4):353-359
Background: A radical forequarter amputation with partial chest wall resection (one to four ribs) has been reported for benign and malignant
lesions involving the shoulder and chest wall region. Concerns about reconstruction and postoperative pulmonary function have
previously limited more extensive chest wall resections. The current report describes the first case in which a complete unilateral
anterior and posterior chest wall resection and pneumonectomy (hemithoracectomy) accompany a forequarter amputation. A novel
reconstructive technique used the full circumference of the forearm tissue with an intact ulna as a free osseomyocutaneous
flap.
Methods: In this case, a 21-year-old patient presented with an extensive recurrent desmoid tumor that involved the shoulder, brachial
plexus, subclavian vein, and chest wall from the lateral sternal border to the midportion of the scapula and down to the eighth
rib. The operative technique involved removal of the entire right hemithorax from the midline sternum to the transverse process
posteriorly, down to the ninth rib inferiorly. Due to the absence of a rigid hemithorax, the uninvolved ipsilateral lung was
also removed. The forearm flap was prepared before final separation of the specimen and division of the subclavian vessels.
Results: Postoperatively, the patient maintained excellent oxygenation without atelectasis or fever and was extubated on the 15th
postoperative day. As expected after pneumonectomy, significant decreases from preoperative to immediate postoperative values
were noted for the vital capacity (VC) (from 4.87 L to 1.29 L), forced 1-s expiratory volume (FEV1) (from 3.77 L to 1.02 L),
and inspiratory capacity (IC) (3.33 1 to 0.99 1). Rehabilitation included a specially designed external prosthesis to provide
cosmesis and prevent scoliosis. By the 15th postoperative week the patient had returned to normal social and physical activities,
with a gradual improvement in all respiratory parameters: VC 1.52 L, FEV1 1.29 L, IC 1.04 L. There has been no evidence of
tumor recurrence at 1 year.
Conclusions: This report provides evidence that a complete hemithoracectomy, pneumonectomy, and forequarter amputation can be safely performed
for selective tumors involving the shoulder region with extensive chest wall invasion. Reconstruction may be achieved with
an extended forearm osseomyocutaneous free flap with an excellent functional outcome.
Presented at the 46th Annual Cancer Symposium of The Society of Surgical Oncology, Los Angeles, California, March 18–21, 1993. 相似文献
85.
A. Barutçu 《European journal of plastic surgery》1994,17(6):316-318
Summary Pedicled temporoparietal fascial flaps have been used extensively in head and neck reconstruction for many years. Also, the fascia has been grafted, and the skin graft transformed into a vascularized pedicled flap (prefabricated temporoparietal fasciocutaneous flap). On the other hand, some authors have used free temporoparietal fascial flaps for defects that require to be filled in lower and upper extremity wounds. In this case, a free prefabricated temporoparietal fascio-chondro-cutaneous flap having only an arterial inflow was used in eyelid reconstruction.Presented at the 14th Congress of Turkish Plastic and Reconstructive Surgery, Ankara, Turkey, October 1992 相似文献
86.
自1986年1月以来,我们使用5种岛状皮瓣为5例小腿及足部骨外露病人修复了创面,效果满意。笔者认为:岛状皮瓣转移术具有手术操作简单,安全可靠,血供丰富,抗感染能力强,术后处理容易等优点。本文还详细介绍了全部病例及手术注意事项。 相似文献
87.
Evidence to suggest the presence of abnormal metabolism of oxygen free radicals in progressive muscular dystrophy is presented using an animal model. In the superficial pectoral muscles of dystrophic chickens, enzyme activities regulating the metabolism of oxygen free radicals, i.e., catalase, superoxide dismutases and glutathione peroxidase, were significantly elevated within 1 week of hatching. Activities of related enzymes, i.e., glutathione reductase, glucose-6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenase were also elevated. In contrast, the specific activity of phosphofructokinase, the rate-limiting enzyme of the glycolytic pathway, was normal during the first 4-week period. These results suggest that there is an increased turnover of oxygen free radicals in the dystrophic muscle. This concept appears important in a further investigation of the pathogenesis and treatment of progressive muscular dystrophies. 相似文献
88.
采用硫代巴比妥酸比色法和亚硝酸盐形成法,分别测定了实验性矽肺大鼠血清过氧化脂质(LPO)及超氧化物歧化酶(SOD)同工酶活力,同时观察了β羧乙基锗倍半氧化物(Ge-132)对实验性大鼠矽肺形成的阻断作用及对自由基代谢的影响。结果显示矽肺大鼠血清LPO含量显著高于对照组,而血清总SOD和CuZnSOD活力显著下降。提示矽肺的发生可能与机体自由基代谢的失衡有关。使用Ge-132可显著提高大鼠机体的抗氧化能力,降低脂质过氧化作用,并可明显干预矽肺病变的形成。 相似文献
89.
应用电子自旋共振波谱仪(ESR)直接检测了缺血-再灌注兔心肌肌浆网自由基的变化,以探讨肌质网系统与氧自由基的关系。实验中将20只兔随机分为再灌注对照组、超氧化物歧化酶(SOD)组、ATP-氯化镁组和人参皂甙Re组。实验结果,g值2.0046处为半醌自由基波谱,其相对浓度各组依次为78.94±2.126,14.46±2.86,20.65±7.65,14.66±3.67(x±SD),对照组与用药组均有显著性差异(P<0.05),表明缺血-再灌注兔心肌肌浆网产生大量的自由基,用ESR可以直接检测到半醌自由基,外源性高能磷酸盐制剂ATP-氯化镁及人参皂甙Re与超氧化物歧化酶一样,发挥清除兔心肌肌浆网自由基的作用。 相似文献
90.
Serum levels of free insulin-like growth factor (IGF)-I were measured by
immunoradiometric assay (IRMA) in fasting sera of 137 normal boys and 120 normal girls
aged from 8 to 15 yr to study relationships between free IGF-I levels and ages, total
IGF-I, IGF binding protein (IGFBP)-1, IGFBP-3, and acid-labile subunit (ALS) levels. In
both sexes, serum free IGF-I levels and the ratios of free IGF-I to total IGF-I were
significantly higher in the pubertal age groups than in the prepubertal age groups. Serum
levels of free IGF-I showed a significant positive correlation with those of total IGF-I,
IGFBP-3 and ALS, while they showed a significant negative correlation with those of
IGFBP-1. These observations suggest that increase in serum free IGF-I levels during
puberty is caused by a dramatic increase in total IGF-I, rather than IGFBP-3, and a
decrease in IGFBP-1. Also, high free IGF-I levels may play an important role in pubertal
growth spurt. 相似文献