Biological characteristics of lactosaminated N-succinyl-chitosan as a liver-specific drug carrier in mice

Lactosaminated N-succinyl-chitosan (Lac-Suc) was prepared by reductive amination of N-succinyl-chitosan (Suc) and lactose using sodium cyanoborohydride. Six-day reaction using lactose (12.8-fold (w/w)) yielded Lac-Suc with lactosamination degree of 30% (mol/sugar unit). Fluorescein thiocarbamyl-Lac-Suc (Lac-Suc-FTC) was prepared by labeling Lac-Suc with fluorescein isothiocyanate. Lac-Suc-FTC was injected intravenously at a dose of either 1 (high dose) or 0.2 (low dose) mg/mouse. At both doses, Lac-Suc-FTC initially underwent fast hepatic clearance, showed maximum liver localization at 8 h, and the amounts localized there were maintained even at 48 h post-injection. Very slow excretion into feces and urine was observed. The ratio of liver AUC_{0–48 h} to plasma AUC_{0–48 h} at low dose was three times higher than that at high dose. On the other hand, the Suc derivative, Gal-Suc, obtained by reductive amination of Suc/galactose showed very little distribution to the liver similarly to Suc itself. Further, since the liver uptake of Lac-Suc-FTC was inhibited by asialofetuin, it was suggested that the liver distribution of Lac-Suc should be concerned with asialoglycoprotein receptor. Thus, Lac-Suc was found available as a carrier exhibiting a high affinity to and long retention in the liver.     

食品添加剂KAl（SO4）2中Al的吸收,排泄,蓄积实验研究

目的：探讨我国主要含铝食品添加剂——硫酸铝钾中铝的吸收、排泄和贮留的基本情况。方法：１．采用６月龄日本雄性大耳兔８只进行３天的代谢平衡实验。２．选用２～３月龄２１只雄性兔进行３２周的蓄积实验。结果：代谢实验表明铝的表观吸收率平均在１０％左右，约９０％的口服铝在粪中排出。尿铝随摄入铝的增加而增加，但肾排铝能力不足吸收的１０％。兔的蓄积实验证明在３２周实验后实验兔随铝摄入的增加其主要脏器均有不同程度的铝蓄积。其蓄积量的顺序为：骨＞肝＞肾＞脑＞心（３．８９～１０５．４６ｍｇ／ｋｇ干重）；蓄积增长倍数为：肝＞脑＞肾＞骨＞心（１．５１～４．５８倍）。结论：１．食品添加剂硫酸铝钾中铝的表观吸收率平均在１０％左右。尿铝随摄入铝的增加而增加，但肾排铝量不足吸收的１０％。２．长期大量摄入含铝食品添加剂可导致机体铝蓄积，其中脑、骨、肝、肾蓄积较明显。     

肾结核误诊分析

目的探讨肾结核误诊原因。方法回顾性分析26例延误诊断肾结核的临床资料。结果延误诊断的成因主要是由于症状不典型、忽视肾结核症状、混淆合并感染或其它泌尿系统疾病及缺乏系统检查有关。结论提高对肾结核特别是对症状不典型肾结核的认识,尿沉渣检查是诊断肾结核的有效方法,PPD试验、B超辅以排泄性尿路造影及CT检查可协助诊断。     

肾盂移行上皮癌诊断的影像学评价

目的:探讨3种常用检查方法在肾盂癌诊断中的价值。方法:对经手术病理证实的21例肾盂移行上皮癌,术前均经螺旋CT、超声、静脉肾盂造影检查,各种检查结果均与肿瘤在肾盂内的生长位置和瘤体高度进行对照。结果:静脉肾盂造影直接诊断肾盂移行上皮癌11例,未显影8例,显示正常2例。超声直接诊断肾盂癌13例,发现肾窦分离提示肾盂癌可能2例,未发现异常6例。螺旋CT直接诊断肾盂癌18例,误诊3例。结论:肾盂肿瘤的生长位置主要影响静脉肾盂造影的诊断;肿瘤的高度主要影响超声的诊断,两者具有明显的互补性。无论在肾盂移行细胞癌病灶的发现还是定性方面,螺旋CT的价值明显优于超声和静脉肾盂造影。     

Bcap—37人乳腺癌细胞系对血卟啉衍生物（HPD）的吸收,分布与排泄

本文报道了Bcap—37人乳腺癌细胞系在体内及体外对血卟啉衍生物(HPD)的吸收、分布与排泄。~3H—HPD经腹腔注入载瘤裸鼠体內后48—72小时,其体内分布含量依次为肝脏>脾脏>肾脏>小肠>肿瘤>皮肤>肌肉>脑组织>血液,表明HPD在体内不同器官的分布有差异性,对Bcap—37乳腺癌细胞有一定的亲和力,但并非特异性集聚于肿瘤组织。体外观察到HPD主要分布于Bcap—37乳腺癌细胞胞质内,细胞核对HPD无明显摄取,提示胞质内一些细胞器是光敏损伤的靶部位。     

Comments on the mechanism of excretion of mercury compounds via bile in rats

While an inorganic mercury compound was excreted in rats via bile with substances of high molecular weight only (fraction 1), MeHg and PhHg compounds were excreted with substances of both high and low (fraction 2) molecular weights. The rate of enterohepatic circulation of the compounds increased and their total excretion from rats decreased with the relatively higher content of the compounds in fraction 2. The bile composition was found to be changed as a result of intoxication by organomercury compounds.     

Influence of spironolactone pretreatment on pharmacokinetics and metabolism of digitoxin in rats

Summary The influence of pretreatment with spironolactone (84 mg/kg at 3 days, twice per day) on the tritium levels in plasma, urine and feces of female SD-rats (n=9) was investigated at various time periods after oral administration of 25 g/kg ³H-digitoxin. In plasma, the concentrations of total radioactivity are reduced in pretreated animals to about 20% of tritium levels in control rats, while the half-life of radioactivity in both groups is almost identical, 2.9 days in pretreated rats and 2.8 days in controls. The lower plasma levels of tritium in pretreated rats coincide with a six-fold decrease in the urinary ³H-elimination and a corresponding increase in the fecal excretion. This is due to a higher biliary clearance of tritiated products in the early phase of elimination. The separation of the excretion products by TLC shows that spironolactone pretreatment enhances the splitting of the glycosidic bonds of digitoxin. The amount of digitoxigenin-bis-digitoxoside and of digitoxigenin-mono-digitoxoside excreted in urine and feces within 96 hrs is four and ten times greater than that recovered in control animals, respectively. The formation of the hydroxylation products digoxin and digoxigenin-bis-digitoxoside is decreased from 50% of the total excreted radioactivity in control to 15% in pretreated rats. The conjugation reactions with glucuronic and sulfuric acid are increased after pretreatment with spironolactone. Thus, the effect of spironolactone on digitoxin kinetics is apparently related to an enhancement of the hepatic excretory mechanism as well as to an enhanced metabolism.Supported by the Deutsche Forschungsgemeinschaft.     

分次团注结合双能量扫描在CTU检查中的应用价值

目的探讨分次团注双能量扫描在降低CTU检查辐射剂量的应用价值。方法 50例行CTU检查的患者平均分两组,其中试验组(A组)25例,行两次团注对比剂后实质期常规扫描和排泄期双能量扫描;对照组(B组)25例,行全泌尿系平扫及单次团注对比剂后实质期和肾孟期常规扫描。A组的数据在工作站上使用双能量后处理软件获得排泄期的最佳ke V图像,将图像的集合系统分段,测量各段管腔内的CT值.并计算对比噪声比(contrast to noise ratio,CNR)。B组排泄期图像发送至同一工作站进行相同的测量和CNR计算,同时记录所有病例完成全部检查的有效辐射量((effetive radiation dose,ERD)),比较两组CT值、CNR、ERD的差别。结果分次团注排泄期最佳ke V图像集合系统的均匀度提高,各段CT值均高于常规图像,其差异有统计学意义(P0.05);与常规排泄期集合系统各段CNR没有统计学意义(P0.05);分次团注双能量方法完成全部检查的ERD(平均12.56 m Sv)明显低于常规CTU(平均18.27m Sv),差异有统计学意义(P0.05)。并能利用双能量软件中的其他功能为诊断提供更多的信息。结论分次团注结合双能量扫描能够有效降低CTU的辐射剂量,提高图像质量。     

动能水对便秘模型小鼠通便功能的影响

目的评价动能水对便秘模型小鼠的润肠通便作用。方法将雄性ICR小鼠随机分为空白对照组、模型对照组、动能水低剂量组、动能水高剂量组和阳性对照组。空白对照组、模型对照组每日灌胃正常饮用水0.3 ml/10 g;动能水低剂量组每日饮用动能水(每日更换);动能水高剂量组除每日饮用动能水外,另灌胃0.3 ml/10 g动能水;阳性药对照组每日0.3 ml/10 g灌胃1次,给药剂量3.3 g/kg,为临床人用量的30倍,造模药物为复方地芬诺酯片。连续灌胃10 d后,观察各组小鼠的首次排黑便时间、5 h内排便粒数及重量和小肠墨汁推进率。结果动能水能显著缩短首次排黑便时间、增加5 h内排便重量和小肠墨汁推进率。结论动能水对小鼠具有一定的通便作用。