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41.
Laura I Sacolick Douglas L Rothman Robin A de Graaf 《Magnetic resonance in medicine》2007,57(3):548-553
Because of their excellent slice profiles and high immunity to RF inhomogeneity, adiabatic full passage (AFP) pulses are ideal for use in spatial localization. The nonlinear, position-dependent phase of a single AFP pulse generated during refocusing of transverse magnetization traditionally is eliminated by using identical pairs of AFP pulses, at the expense of increased RF power deposition and increased echo time (TE). Here it is shown that one can achieve significant phase refocusing by executing single AFP pulses along non-equivalent spatial axes. When used for volume selection in MR spectroscopic imaging (MRSI) the remaining nonlinear phase becomes inconsequential when the phase across a spectroscopic volume is small. Selection of rectangular and octagonal volumes is demonstrated with half the number of AFP pulses used in the traditional approach. It is shown that octagonal volume selection in the human brain provides excellent suppression of extracranial lipids, and thus allows multislice (1)H MRSI at 4 Tesla to be performed within the guidelines for RF power deposition. 相似文献
42.
W. Vaudry R. Ettenger P. Jara G. Varela-Fascinetto M. R. Bouw J. Ives R. Walker 《American journal of transplantation》2009,9(3):636-643
Oral valganciclovir is effective prophylaxis for cytomegalovirus (CMV) disease in adults receiving solid organ transplantation (SOT). However, data in pediatrics are limited. This study evaluated the pharmacokinetics and safety of valganciclovir oral solution or tablets in 63 pediatric SOT recipients at risk of CMV disease, including 17 recipients ≤2 years old. Patients received up to 100 days' valganciclovir prophylaxis; dosage was calculated using the algorithm: dose (mg) = 7 × body surface area × creatinine clearance (Schwartz method; CrCLS). Ganciclovir pharmacokinetics were described using a population pharmacokinetic approach. Safety endpoints were measured up to week 26. Mean estimated ganciclovir exposures showed no clear relationship to either body size or renal function, indicating that the dosing algorithm adequately accounted for both these variables. Mean ganciclovir exposures, across age groups and organ recipient groups were: kidney 51.8 ± 11.9 μg * h/mL; liver 61.7 ± 29.5 μg * h/mL; heart 58.0 ± 21.8 μg * h/mL. Treatment was well tolerated, with a safety profile similar to that in adults. Seven serious treatment-related adverse events (AEs) occurred in five patients. Two patients had CMV viremia during treatment but none experienced CMV disease. In conclusion, a valganciclovir-dosing algorithm that adjusted for body surface area and renal function provides ganciclovir exposures similar to those established as safe and effective in adults 相似文献
43.
《Journal of labelled compounds & radiopharmaceuticals》2003,46(6):567-574
The development of combined microwave‐enhanced/parallel synthesis procedures and their application to the deuteriation of organic compounds via examples of solid‐state hydrogenation is reported. Other labelling procedures, such as solution state catalytic dehalogenations, hydrogenations as well as hydrogen isotope exchange reactions also benefit from the combined technology. Copyright © 2003 John Wiley & Sons, Ltd. 相似文献
44.
45.
Iron overload and liver fibrosis 总被引:1,自引:0,他引:1
MJP ARTHUR 《Journal of gastroenterology and hepatology》1996,11(10):1124-1129
46.
Permeability of pure lipid bilayers to melatonin 总被引:9,自引:1,他引:8
Ernane J.X. Costa Roberto Harzer Lopes M. Teresa Lamy-Freund 《Journal of pineal research》1995,19(3):123-126
Abstract: Melatonin, the chief hormone of the pineal gland, has been reported to interact with a variety of different cells. This ubiquitously acting hormone has been found to interact with protein receptors both at the cell membrane and in the nucleus. Moreover, melatonin was recently shown to be a very potent hydroxyl radical scavenger. The present work focuses on the interaction of melatonin with pure lipid bilayers. It is shown that melatonin can cross multilamellar lipid vesicles, which are used here as model systems for the lipid phase of biological membranes. Thus, the data prove that melatonin can easily pass through the cell membrane and bath every part of the cell, as previously suggested in the literature. Melatonin lipid association constant was calculated based on the change of the hormone fluorescence intensity due to its penetration into the hydrophobic lipid phase. Though melatonin was recently shown to be highly soluble in aqueous media, its lipid association constant is rather high, indicating that the biological action of the hormone is likely to be at the membrane level, either via its interaction with membrane receptors, and/or as a lipoperoxidation radical scavenger. 相似文献
47.
豆渣纤维的降脂作用及对血液流变学影响的研究 总被引:19,自引:1,他引:18
以SD大鼠为对象,研究了豆渣纤维对高胆固醇膳动物脂质代谢和血流变性的影响,并与果胶和纯纤维素进行比较,结果表明:8周实验后,豆渣与果胶组动物的血清总胆固醇(TC)和低密度脂蛋白胆固醇(LDL-C)显著降低,但豆渣组的血脂水平比果胶组更低(P<0.05)。而纯纤维素组未显出降脂作用。各组大鼠的甘油三醋(TG)和高密度脂蛋白胆固醇(HDL-C)也无明显变化。实验同时表明,6%的豆渣纤维与果胶均可使高脂大鼠的血粘度及血小板聚集率降低(P<0.05),且前者优于后者。相关分析显示,血脂与血流变学指标间存在显著相关性(P<0.05),其中TC与LDL-C是影响血流变性的重要因素。6%的以上各种纤维摄入量均不影响大鼠的摄食量与生长。 相似文献
48.
本文报道给C57小鼠腹腔注射不同剂量1-甲基-4-苯基-1,2,3,6-四氢吡啶(MPTP)后,发现组3(MPTP35 mg/kg,每天一次,共7天)鼠肝匀浆、线粒体和微粒体的膜丙二醛含量明显增加,与对照组相比分别增加70.5%,67%和51.4%(P<0.01),而组1(MPTP 35mg/kg,每4小时一次,共3次)和组2(MPTP35mg/kg,每天一次,共4天)鼠肝丙二醛含量与对照组相近。结果表明MPTP有明显地促进鼠肝脂质过氧化的作用,并与其剂量有关。 相似文献
49.
Age, hematopoietic growth factors, cyclosporin A, mode of bone marrow transplantation (BMT) (autologous, allogeneic-related,
unrelated), and underlying disease were assessed as potential risk factors for capillary leakage syndrome (CLS) in 96 patients
after BMT. CLS was defined as unexplained weight gain of >3% within 24 h and nonresponsiveness to furosemide. CLS occurred
in 9/21 patients after unrelated compared with 2/33 after allogeneic-related BMT (p=0.0017) for hematopoietic disorders (n=54) and in 6/7 patients after allogeneic-related compared with 3/35 after autologous BMT (p=0.0001) for solid tumors (n=42). Hematopoietic growth factors and cyclosporin A were no signficant risk factors on their own. We conclude that unrelated
BMTs or high-intensity conditioning regimens used in combination with allogeneic-related BMT are the main risk factors for
CLS.
Received: 6 January 1997 / Accepted: 10 March 1997 相似文献
50.
目的:观察地尔硫对冠心病病人的抗脂质过氧化及抗氧自由基作用。方法:冠心病病人30例为治疗组(男性21例,女性9例,年龄58±s6a),给予地尔硫30mg,po,tid,共4wk。健康人组30例(男性18例,女性12例,年龄58±9a)。结果:治疗组在给药前较健康人组的血清oxLDL,LPO,SCL,LCL值显著升高,P<0.01,GSH-Px显著降低,P<0.01,SOD活力两者无明显差异,P>0.05。治疗组用药后与用药前相比oxLDL,LPO,SCL,LCL值显著下降,P<0.01或<0.05,GSH-Px显著升高,P<0.01,治疗组治疗后与健康人组相比,除LCL外,其他指标皆无明显差异,P>0.05。结论:地尔硫是一良好的抗氧化剂。 相似文献