实验性糖尿病大鼠肾脏损害和脂质过氧化物水平的动态研究

动态观察实验性糖尿病大鼠于发病后２、４、６、１２、和１６周肾脏损害指标和肾脏脂质过氧化物（ＬＰＯ）水平的变化。结果表明，发病后各观察时间．或糖尿病大鼠２４ｈ尿Ａｌｂ、β２──ＭＧ排泄量和尿ＮＡＧ活性均明显增高，而２４ｈ尿ＴＨＰ排泄量显著降低，肾脏ＬＰＯ水平明显升高。其中尿ＮＡＧ活性、ＴＨＰ排泄量和肾脏ＬＰＯ水平均随病程延长而更趋明显。这些结果提示，在糖尿病早期除有肾小球功能损害外，肾小管也明显受损，过氧化损伤在糖尿病肾病发病中可能是重要因素之一。尿Ａｌｂ、β２──ＭＧ、ＴＨＰ含量和ＮＡＧ活性可作为糖尿病肾病早期肾损害的敏感指标。     

有机锗对大鼠实验性矽肺形成及脂质过氧化水平的影响

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。     

复方通络中药改善肥胖患者血管内皮细胞功能障碍研究

目的观察复方通络中药对单纯性肥胖患者血管内皮依赖性舒张功能障碍的干预效应，探讨其作用机制。方法应用高分辨血管超声检查选择血管内皮依赖性舒张功能障碍[以血流介导的肱动脉扩张率（FMD）表示]肥胖患者（65例），随机分为通络中药治疗组和对照组。治疗组32例，对照组33例。治疗组给予辛香疏络2号胶囊，3g／次，每日3次；对照组给予淀粉胶囊，3g／次，每日3次。共用药12周，分别测定用药前后FMD、肱动脉内径（D0），同时检测辛香疏络2号治疗前后患者血清总胆固醇（TC）、三酰甘油（TG）的变化。结果治疗后治疗组FMD较对照组明显增加（P〈0．01），TC、TG较治疗前及对照组明显下降（P〈0．01）。结论复方通络中药辛香疏络2号胶囊可明显改善肥胖患者血管内皮障碍，调节血脂可能是其改善血管内皮功能机制之一。     

Fast decomposition of water and lipid using a GRASE technique with the IDEAL algorithm.

Three-point Dixon techniques achieve good lipid-water separation by estimating the phase due to field inhomogeneities. Recently it was demonstrated that the combination of an iterative algorithm (iterative decomposition of water and fat with echo asymmetry and least-squares estimation (IDEAL)) with a fast spin-echo (FSE) three-point Dixon method yielded robust lipid-water decomposition. As an alternative to FSE, the gradient- and spin-echo (GRASE) technique has been developed for efficient data collection. In this work we present a method for lipid-water separation by combining IDEAL with the GRASE technique. An approach to correct for errors in the lipid-water decomposition caused by phase distortions due to the switching of the readout gradient polarities inherent to GRASE is presented. The IDEAL-GRASE technique is demonstrated in phantoms and in vivo for various applications, including pelvic, musculoskeletal, and (breath-hold) cardiac imaging.     

Water- and fat-suppressed proton projection MRI (WASPI) of rat femur bone.

Investigators often study rats by microCT to investigate the pathogenesis and treatment of skeletal disorders in humans. However, microCT measurements provide information only on bone mineral content and not the solid matrix. CT scans are often carried out on cancellous bone, which contains a significant volume of marrow cells, stroma, water, and fat, and thus the apparent bone mineral density (BMD) does not reflect the mineral density within the matrix, where the mineral crystals are localized. Water- and fat-suppressed solid-state proton projection imaging (WASPI) was utilized in this study to image the solid matrix content (collagen, tightly bound water, and other immobile molecules) of rat femur specimens, and meet the challenges of small sample size and demanding submillimeter resolution. A method is introduced to recover the central region of k-space, which is always lost in the receiver dead time when free induction decays (FIDs) are acquired. With this approach, points near the k-space origin are sampled under a small number of radial projections at reduced gradient strength. The typical scan time for the current WASPI experiments was 2 hr. Proton solid-matrix images of rat femurs with 0.4-mm resolution and 12-mm field of view (FOV) were obtained. This method provides a noninvasive means of studying bone matrix in small animals.     

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.     

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。