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81.
Thomas A. Churchill Colin J. Green Brian R. Davidson Barry J. Fuller 《Transplant international》1995,8(5):374-381
In previous experimental liver transplant studies, it was possible to extend cold ischaemic time (CIT) by using a flush/storage solution combining histidine, lactobionate and raffinose (HLR). In this study, energy metabolism, glycolytic substrate (glucose) and anaerobic end-product (lactate) were examined in rat liver over 24 h of cold storage to determine the mechanism of action of the HLR solution. In livers subjected to simple flush and storage with the HLR solution. levels of ATP and ADP were considerably higher than livers stored with modified UW throughout 24 h of storage; at 4 h of storage, ATP and ADP levels were 1.1 and 3.1 mol/g for HLR solution versus 0.18 and 0.81 mol/g for UW solution. Total adenylate contents (TA=ATP+ADP+AMP) also remained 1–2 mol/g higher in HLR-treated livers than those preserved in UW; TA values ranged from 3.8 to 5.7 mol/g. Glucose increased to 20–35 mol/g by 10–24 h of storage (similar to the UW group). Lactate rose to almost twice that in livers stored in UW; total lactate accumulation was approximately 10.0 mol/g. This study demonstrated that the combined HLR solution is able to prolong the maximum safe CIT by increasing anaerobic metabolism and consequently preserving liver energetics. The second part of the experiment examined the effect of continuous perfusion (with/without O2) over the 1st h of cold ischaemia. Under current methods of liver flushing and excision, the 1st h of cold storage may be the critical time of metabolic adjustment since most of the pH and ATP changes occur during this period. Therefore, we tested the hypothesis that the combination of a simple flush with an additional brief 1-h perfusion period prior to storage would enhance the maintenance of hepatic energetics. There was no beneficial effect of 1 h of perfusion without O2 compared to simple HLR flush and storage. However, perfusion with O2 resulted in prolonged maintenance of high energy adenylates and total adenylates; at 10 h of storage ATP was 1.0, ADP 3.3, and TA 5.7 mol/g. However, any improvement in ultimate viability following long-term storage of the livers in these two groups needs to be tested in an animal transplant model. 相似文献
82.
Summary In this experimental study, a neodymiumyttrium-aluminium-garnet (NdYAG) laser was used to induce highly reproducible focal spinal cord lesions in anaesthetized guinea pigs. The efficacy of high dose amino acid solution (HDAAS) on this injury is investigated. Experiments were performed on 36 animals divided into three groups; sham operated controls, laser irradiated surgical controls, and amino acid groups. Acute responses to injury were evaluated with somatosensory (SSEP) and motor evoked potentials (MEP) and functional recovery was assessed for 8 weeks using the inclined plane technique.In the laser irradiated surgical control group, MEP disappeared one hour after the laser injury, but SSEP revealed changes of amplitude and latency. In this group, the average value of the inclined plane at 24 hours after the laser application was 45.3±1.4 degrees. In the amino acid group, at the sixth hour of injury, MEP and SSEP changes improved with infusion of HDAAS for 4 hours. This improvement was statistically significant (for latency of SSEP U=140 p<0.05). Inclined plane value at 24 hours after the laser application was 65.5±1.2 degrees in this group.This study showed that application of NdYAG laser irradiation on the spinal cord induced spinal cord injury which presented as paraparesis, HDAAS may provide significant therapeutic protection in secondary damage following this injury and may have a potential role in the treatment of acute spinal cord injury. 相似文献
83.
目的:评价新型长效β2激动剂——盐酸班布特罗口服液治疗支气管哮喘的疗效和安全性。方法:采用随机单盲对照和开放试验,对101例哮喘患者进行为期4周、口服盐酸班布特罗口服液、10~20mg每晚一次的疗效观察,并进行剂量滴定。结果:治疗组(50例)和开放组(51例)临床控制率分别为54.0%和62.5%,有效率分别为88.0%和92.7%。治疗2周,肺功能即显著改善。剂量滴定试验提示部分患者的合适剂量为每日20mg。不良反应发生率为7.9%。主要表现为手抖、心悸和头晕,不影响治疗。1例出现一过性血清丙氨酸转氨酶(ALT)轻度升高。结论:盐酸班布特罗口服液是安全而有效的,是一种长效支气管扩张药物。 相似文献
84.
采用体积排斥色谱法/ 示差折光指数/ 直角激光光散射/ 示差粘度三检测联用技术表征了氘化聚苯乙烯、聚苯乙烯和氘化聚苯乙烯- 聚异戊二烯。结果表明,在θ条件下,虽然氘化聚苯乙烯的化学依赖性常数υT,DPS比聚苯乙烯的化学依赖性常数υT,PS大,但25 ℃时在四氢呋喃中,氘化聚苯乙烯的分子尺寸仍小于聚苯乙烯的分子尺寸。由于嵌段共聚物的淋洗体积随组成变化,所以用传统的SEC/RI得不到准确的分子量。经比较膜渗透、小角激光光散射和基质辅助激光脱吸与离子化时间飞行质谱等的实验结果,证明体积排斥色谱法/ 示差折光指数/ 直角激光光散射/ 示差粘度三检测技术能准确地得到氘化二嵌段共聚物的分子量以及其它重要信息。 相似文献
85.
观察机械性损伤的海马神经细胞在不同浓度高晶体- 高胶体渗透压溶液中容积的变化。取原代培养大白鼠胚胎的海马神经细胞,用超声波机械损伤细胞后暴露于含0.5 g/L、1 g/L和2.5 g/L氯化钠的细胞培养基中15 m in。结果显示机械性损伤的细胞明显肿胀(P< 0.05)。当细胞暴露于不同浓度的高晶体- 高胶体溶液15 m in 后, 细胞容积与同一实验时间的对照值相比明显下降, 并保持至第7 d (P< 0.05)。表明受到机械性损伤的海马神经细胞在高晶体- 高胶体渗透压环境中的容积调节功能丧失或减弱。 相似文献
86.
Gangwar Sanjeev Jois Seetharama D. S. Siahaan Teruna J. Vander Velde David G. Stella Valentine J. Borchardt Ronald T. 《Pharmaceutical research》1996,13(11):1657-1662
Purpose. To determine the different conformations of the acyloxyalkoxy-linked cyclic prodrug 1 of the model hexapeptide 2 in solution and to investigate the relationship between these solution conformations and the cellular permeability characteristics of this prodrug.
Methods. Two-dimensional Homonuclear Hartmann-Hahn spectroscopy, Rotating-Frame Overhouser effect spectroscopy, circular dichroism and molecular dynamics simulations were used to find the solution conformers of cyclic prodrug 1.
Results. Our spectroscopic findings suggest that cyclic prodrug 1 exhibits a major and a minor conformer in solution. The major conformer appears to have a well-defined secondary structure, which involves a -turn and 4 1 intramolecular hydrogen bond, creating a compact structure with a reduced average hydrodynamic radius compared to the model hexapeptide 2.
Conclusions. The increased ability of cyclic prodrug 1 to permeate membranes compared to the model hexapeptide 2 could be due to reduction in the average hydrodynamic radius of the molecule facilitating paracellular flux and/or the reduction in the hydrogen bonding potential facilitating transcellular flux. 相似文献
87.
88.
喉咽灵口服液的体外抗菌作用 总被引:2,自引:0,他引:2
目的:探讨喉咽灵口服液的体外抗菌作用。方法:为临床分离细菌为受试菌,采用连续倍比稀释法,观察喉咽灵口服液的最低抑菌浓度和最低杀菌浓度。结果:喉咽灵口服液对不同细菌的最小抑菌浓度是成品浓度64-128倍,最小杀菌浓度是成品浓度32-64倍。结论:喉咽灵口服液对所有受试菌均有不同程度的抑菌和杀菌作用,且抗菌谱广,抗菌作用强。 相似文献
89.
RP-HPLC测定上感口服液中丹皮酚含量 总被引:2,自引:2,他引:2
应用RP -HPLC测定上感口服液中丹皮酚的含量。采用ODS色普柱 ( 2 5 0mm× 4 6mm ,5 μm) ,甲醇-水 -冰醋酸 ( 65∶35∶0 5 )为流动相 ,检测波长为 2 74nm。丹皮酚在 2 5~ 30 μg ml-1浓度范围内呈良好线性关系 (r =0 9999) ,平均回收率为 95 7%,RSD =2 1%(n =6)。方法准确、灵敏 ,回收率高。 相似文献
90.
目的合成一系列温度敏感性(温敏性)凝胶,测定其低临界溶液温度(相变温度)。筛选出具有与人体体温相近的相变温度的凝胶,并使其可以作为药物的载体。方法采用自由基水溶液聚合的方法合成共聚物,然后用聚合物承载药物并用高效液相色谱法测其不同温度下药物的释放情况。结果温敏性凝胶可以作为自控式或缓释药用辅料,但如果相变温度低于人体体温,则无实际应用意义。采用共聚合的方法,确可提高凝胶的相变温度。不同条件下合成的共聚物有着不同的相变温度,药物释放情况也不同。结论调整不同组成比例及交联剂的浓度,可使此类凝胶作为自控式或缓释药用辅料成为可能。 相似文献