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991.
主动载药法制备盐酸去氢骆驼蓬碱脂质体 总被引:5,自引:0,他引:5
目的制备高包封率的盐酸去氢骆驼蓬碱脂质体。方法处方前研究测定了药物在不同pH值缓冲液中的溶解度和表观油水分配系数;采用pH梯度进行主动载药。超滤法分离脂质体与游离药物,测定包封率,考察了外水相pH值、孵育温度、药脂比对包封率的影响。结果随pH值的增大,盐酸去氢骆驼蓬碱的溶解度降低,表观油水分配系数增大;采用主动载药法,包封率随脂质体内外相pH梯度的减少而降低,受孵育温度的影响不大,在药脂比小于1∶5时脂质体包封率达到80%以上。结论主动载药法可制得包封率较高的去氢骆驼蓬碱脂质体。 相似文献
992.
Rui Guo Xing-Ya Gao Wei Wang Han-Jun Wang Feng Zhang Ying Zhang Guo-Qing Zhu 《Pharmacological research》2005,52(2):192-198
The generation of reactive oxygen species (ROS) contributes to reperfusion-induced arrhythmias. In the present study, the antiarrhythmic effects of tempol and tiron, two membrane-permeable radical scavengers, on reperfusion-induced arrhythmias in rats in vivo were investigated. The anaesthetized rats were subjected to 5 min of left descending coronary artery (LAD) occlusion followed by 30 min of reperfusion. All rats pretreated with saline developed ventricular tachycardia (VT) and ventricular fibrillation (VF) at the onset of reperfusion, and most of the rats died from irreversible VF at the end of reperfusion. However, pretreatment with tempol (30 or 100 mg kg(-1)) 5 min before reperfusion reduced mortality, arrhythmia score and the incidence and duration of VT and VF. In the rats pretreated with high dose of tempol (100 mg kg(-1)), no VF happened and all rats were alive at the end of the experiment. The arrhythmia score was also significantly decreased compared with that of rats pretreated with saline (0.80 +/- 0.4 versus 5.6 +/- 0.4, P < 0.01). Tiron also provided nearly complete protection against reperfusion-induced arrhythmias when given 2 min before reperfusion. On the other hand, intravenous administration of tempol induced decreases in mean arterial pressure (MAP), heart rate (HR) and pressure rate index (PRI), a relative indicator of myocardial oxygen consumption. In order to determine whether the antiarrhythmic effects of tempol were secondary to the reduction of myocardial oxygen consumption, continuous electrical stimulation of the aortic depressor nerve (3 V, 10 ms and 10 Hz) was carried out in a group of rats to induce decreases in MAP, HR and PRI similar to those in the high dose of Tempol group. However, these rats did not show significant changes in the severity of reperfusion-induced arrhythmias. We conclude that both tempol and tiron significantly reduce reperfusion-induced arrhythmias in rats, and this protective action is independent of hemodynamic effects. 相似文献
993.
目的:观察体温筛选寒热体鼠自然模型的可靠性及对子代的影响.方法:通过测定大鼠肛温将其分为"寒体""热体"组,测定血糖、尿儿茶酚胺含量,雌雄鼠交配,检测子代肛温、血糖、尿儿茶酚胺、胰岛素及丙二醛含量.结果:热体鼠血糖、尿儿茶酚胺含量均高于寒体鼠,热体组子代肛温、尿儿茶酚胺、血糖及丙二醛含量均高于寒体组.结论:体温筛选寒热体鼠自然模型可靠,寒热体鼠体温、血糖呈遗传态势,热体鼠氧化过激反应显著. 相似文献
994.
川芎内酯A预处理对大鼠离体心脏缺血再灌注所致血管内皮细胞损伤的保护作用 总被引:6,自引:4,他引:6
目的:观察川芎内酯A预处理对大鼠离体心脏缺血再灌注所致血管内皮细胞损伤的保护作用。方法:采用Langendorff离体心脏灌流方法,在恒温恒压条件下,以0.5mL.min-1的灌流速度给药,剂量分别为0.05,0.025,0.0125g.L-1与K-H灌流液同时灌流心脏10min;全心停灌30min,再灌60min。结果:川芎内酯A预处理能提高大鼠离体心脏停灌再灌期的冠脉流量;降低冠脉流出液中IL-1β浓度和TXB2/6-Keto-PGF1α的比值;室性心动过速(VT)和心室颤动(VF)的发生率降低,VT,VF持续时间缩短;心肌匀浆液乳酸脱氢酶、丙二醛的含量降低,超氧化物歧化酶活性提高。结论:川芎内酯A预处理对大鼠离体心脏停灌再灌注损伤所致的血管内皮细胞损伤可能具有保护作用。 相似文献
995.
羟基喜树碱腹腔内给药的药代动力学研究 总被引:2,自引:0,他引:2
目的:研究羟基喜树碱(HCPT)腹腔内给药的药代动力学特点。方法:比格犬6只,HCPT剂量2 mg.kg-1,溶于50 mL生理盐水中,先腹腔内注入250 mL生理盐水,随后用恒速泵快速注入HCPT;随后按不同时间点抽取血液和腹腔液,各样本用高效液相色谱分析药物浓度,并用3p87软件包计算药代动力学参数。结果:腹腔液HCPT的AUC与外周静脉血及门静脉血AUC之间的比值分别为45∶1和37∶1,P值均小于0.001;腹腔液HCPT浓度明显高于外周静脉给药组的腹腔液浓度,峰值为60.4倍,AUC为21倍。P值均小于0.001。结论:腹腔内给药其药代动力学具有明显优越性,能维持腹腔液和门静脉血更高更持久的血药浓度,因而有利于化疗药物发挥更大的生物学效应,值得临床应用。 相似文献
996.
997.
针刺治疗急性腰扭伤78例 总被引:1,自引:0,他引:1
急性腰扭伤俗称"闪腰"、"岔气",古代文献称为"概腰",是一种急性要部软组织扭伤,也是针灸科常见病之一.它主要是在运动或劳动中,用力不当、过度负重、超过生理负荷,使腰部受到强大的牵扯或行走跑跳、直接或间接暴力造成的腰肌韧带、关节囊、筋膜软织损伤,局部毛细血管破裂,肌腱韧带撕裂易位,关节囊撕破等,从而使局部组织液渗出,充血水肿,出现气血凝滞,经脉痹阻,进而肌肉痉挛,功能活动受限,动作不协调,局部压痛拒按,咳嗽、深呼吸时疼痛加重. 相似文献
998.
Parathyroid hormone-related protein (PTHrP) and the PTH/PTHrP receptor are expressed in most normal tissues, including brain, where PTHrP is though to act locally in an autocrine or paracrine fashion. Previous in situ localization studies in adult rodents have documented CNS PTHrP expression in neurons but not in glial cells. However, a recent report describing immunoreactive PTHrP in human astrocytomas suggests that PTHrP expression may be a marker of dedifferentiation and/or malignant transformation in glial cells. To begin to test this hypothesis, constitutive and regulated PTHrP expression were examined in cultured fetal and transformed (U-373 MG) human astrocytes. PTHrP was expressed in untreated fetal astrocytes and U-373 MG cells, as determined by Northern analysis, immunocytochemical staining, and detection of PTHrP(1-84) protein in conditioned media. Epidermal growth factor and tumor necrosis factor, important growth factors in astrocyte development and malignant transformation, stimulated PTHrP expression in both cell types. Treatment of U-373 MG cells or fetal astrocytes with PTHrP(1-34) consistently inhibited cellular proliferation, as measured by [(3)H]-thymidine incorporation. These findings suggest that PTHrP, a peptide whose expression is induced by mitogens in both immature and transformed human astrocytes, may feedback inhibit cellular proliferation, an effect that may be of importance during malignant transformation as well as CNS development. Furthermore, when combined with previous evidence of PTHrP expression by PTH/PTHrP receptor-positive neurons, our demonstration of regulated PTHrP expression by receptor-positive astrocytes identifies PTHrP as a potential peptide mediator of cross-talk between glial cells and neurons. 相似文献
999.
Ge Y Udupa JK Nyúl LG Wei L Grossman RI 《Journal of magnetic resonance imaging : JMRI》2000,12(5):715-721
Image intensity standardization is a recently developed postprocessing method that is capable of correcting the signal intensity variations in MR images. We evaluated signal intensity of healthy and diseased tissues in 10 multiple sclerosis (MS) patients based on standardized dual fast spin-echo MR images using a numerical postprocessing technique. The main idea of this technique is to deform the volume image histogram of each study to match a standard histogram and to utilize the resulting transformation to map the image intensities into standard scale. Upon standardization, the coefficients of variation of signal intensities for each segmented tissue (gray matter, white matter, lesion plaques, and diffuse abnormal white matter) in all patients were significantly smaller (2.3-9.2 times) than in the original images, and the same tissues from different patients looked alike, with similar intensity characteristics. Numerical tissue characterizability of different tissues in MS achieved by standardization offers a fixed tissue-specific meaning for the numerical values and can significantly facilitate image segmentation and analysis. 相似文献
1000.
复方溴氯海因消毒剂性能的试验观察 总被引:1,自引:1,他引:1
目的 研究复方溴氯海因消毒剂的性能。 方法 在实验室我们分别进行悬液定量杀灭试验、稳定性试验、毒性试验。 结果 复方溴氯海因消毒剂为含溴氯海因的片剂 ,含有效氯 471g/kg ,以含复方溴氯海因消毒剂 1:2 0 0 0(g/ml)的稀释液对大肠杆菌、金黄色葡萄球菌分别作用 5、10min的杀灭对数值各次均大于 5 .0 0。含复方溴氯海因消毒剂 1:2 0 0 (g/ml)的稀释液对白色念珠菌作用 10min的杀灭对数值各次均大于 4.0 0。现场试验表明 ,消毒效果好。该片剂置 3 7℃温箱 90d后 ,其有效氯含量下降率 1.74%。毒性试验显示 ,急性经口毒性试验表明该片剂属实际无毒 ;无刺激性 ;微核试验结果为阴性 ;2 0 0mg/kg·bw为最大未观察到有害作用剂量 ,10 0 0mg/kg·bw为最小观察到有害作用剂量。 结论 复方溴氯海因消毒剂属于一类杀菌广谱、高效、无毒、稳定性好的消毒剂。 相似文献