Adiabatic refocusing pulses for volume selection in magnetic resonance spectroscopic imaging.

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.     

瘦素、胆囊收缩素、血脂与胆石类型关系探讨

目的探讨瘦素（leptin）、缩胆囊肽（CCK）、血脂、胆固醇与Gs和HS两类胆石病关系。方法比较检测339例胆囊结石（Gs），67例肝胆管结石（HS）病员，20例正常对照者血清leptin、CCK、胰岛素、肝功能、血脂、脂蛋白等，评价各检测指标间关系。结果GS组leptin、CCK、BMI、胆固醇、甘油三酯、白蛋白、GGT、APO-a显著高于HS组（P〈0．05）；GS组内leptin与CCK、BMI、胰岛素、转氨酶、胆红素、胆固醇呈正相关（P〈0．05）；HS组内leptin与CCK、BMI、胰岛素、转氨酶、胆红素呈正相关（P〈0．01），与白蛋白、APO-a呈负相关（P〈0．05）。结论Leptin参与调控脂质代谢，两类胆石Leptin、血脂等存在明显差别，从调控脂质代谢角度探讨Leptin在两类胆石中的作用可能对阐明胆石成因具有价值。     

颈动脉粥样硬化斑块与脑梗死关系的研究

目的:研究颈动脉粥样硬化斑块与脑梗死发生的关系,以及血脂、血糖、纤维蛋白原(Fbg)等在颈动脉粥样硬化形成中的影响。方法:对51例脑梗死病人行颈动脉超声检查,按有无粥样硬化斑块分成两组,比较其神经功能缺损情况及血液中TC、TG、LDL、HDL-C、apoprotein Al、apoprotein B、空腹血糖(FBG)和Fbg的含量;观察梗死侧与非梗死侧的颈动脉粥样硬化斑块发生率。结果:脑梗死病人的颈动脉粥样硬化斑块发生率为70.6％,与无斑块组比较,两组的神经功能缺损评分差异元显著性(P>0.05)。斑块组TC、LDL、aporprotein B、FBG及Fbg较无斑块组增高(P<0.05),HDL-C的含量则降低(P<0.05);梗死侧颈动脉粥样硬化斑块发生率增高(P<0.05)。结论:定期颈动脉超声和对血脂血糖等检查,可作为早期发现和筛选脑梗死高危病人的重要手段。     

Valganciclovir Dosing According to Body Surface Area and Renal Function in Pediatric Solid Organ Transplant Recipients

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     

板蓝根磷脂对内毒素血症小鼠巨噬细胞膜脂流动性的影响

目的　以小鼠内毒素血症为模型 ,观察板蓝根磷脂对内毒素血症小鼠巨噬细胞膜脂流动性的保护作用。方法　小鼠分为板蓝根氯仿提取物预处理组、磷脂脂质体预处理组、板蓝根磷脂脂质体预处理组和内毒素血症对照组。各组按照上述次序分别给予腹腔注射 5ml/kg相应药物 ,预处理 18h后腹腔注射内毒素 6mg/kg。 6h后处死小鼠 ,观察细胞膜脂流动性的变化。结果　板蓝根氯仿提取物对内毒素血症小鼠巨噬细胞膜脂流动性的保护作用没有达到具有统计学意义的程度 (P >0 .0 5 ) ,磷脂脂质体对膜脂流动性具有保护作用 (P <0 .0 5 ) ,但两者之间并没有统计学上的差别 (P >0 .0 5 ) ;板蓝根磷脂对内毒素血症小鼠细胞膜脂流动性具有明显的保护作用 (P <0 .0 1) ,优于单独使用板蓝根氯仿提取物 (P <0 .0 5 )或磷脂脂质体 (P =0 .0 5 )。结论　板蓝根磷脂脂质体对内毒素血症小鼠巨噬细胞膜脂流动性的保护作用优于单独使用板蓝根氯仿提取物或磷脂脂质体     

Combining microwave‐enhanced deuteriation reactions with parallel synthesis procedures

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.     

通塞益脑液治疗急性脑梗塞的机理探讨

本文以结扎左侧颈总动脉造成实验性急性脑梗塞的沙土鼠模型,探讨通塞益脑液治疗急性脑梗塞的机理。发现结扎术前胃饲通塞益脑液者,可降低急性脑梗塞后脑组织中过氧化脂质的含量;结扎术后给药者,可降低脑组织中钙的含量。初步认为通塞益脑液对急性脑梗塞的脑组织有保护作用。     

Permeability of pure lipid bilayers to melatonin

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.     

豆渣纤维的降脂作用及对血液流变学影响的研究

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。