Immunohistochemically demonstrated variation in expression of cathepsin E between uracil-induced papillomatosis and N-butyl-N-(4-hydroxybutyl)nitrosamine-induced preneoplastic and neoplastic changes in rat urinary bladder

Expression of rat urinary bladder cathepsin E in benign papillomatosis induced by uracil and various stages of N-butyl-N-(4-hydroxybutyl)nitrosamine (BBN)-induced carcinogenesis was investigated immunohistochemically. Seven-week-old, male F344/DuCrj rats were used. In the normal urothelium of control rats, cathepsin E stained in all layers of cells, although in umbrella cells and some basal cells the reaction was relatively weak. In rats given a diet containing 3% uracil for 5 weeks immunoreactivity of cathepsin E in uracil-induced papillomatosis was consistently homogeneous in all layers, but weaker than in normal urothelium. In rats given 0.05% BBN in drinking water for 12 weeks and subsequently maintained without treatment for 48 weeks cells with little cathepsin E, never observed in normal urothelium, appeared at 5 weeks above the basement membrane in the earliest stage of BBN-induced urinary bladder cancer (simple hyperplasia). Throughout the neoplastic process, groups of cells with a little cathepsin E were randomly distributed, with expression in the urothelium being markedly unstable. Almost all areas of squamous cell proliferation in TCC were negative for cathepsin E. Instability of cathepsin E expression in rat urothelium therefore appears characteristic for carcinogenesis and offers the possibility of using this feature as an early biomarker for urinary bladder carcinogenesis.     

Chromosomal mapping of the uracil permease gene of Saccharomyces cerevisiae

Summary The gene FUR4, coding for the uracil permease in Saccharomyces cerevisiae, was mapped on chromosome II, at a distance of 7.8 cM from the centromere on the right arm of the chromosome. In a first step, we used the chromosome loss mapping method developed by Falco and Botstein (1983) to determine on which chromosome the gene mapped. After the observation that FUR4 was closely linked to GAL10, one of the three genes forming the gal cluster (Bassel and Mortimer 1971), we could determine precisely the position of the gene on chromosome II.     

UPLC法同时测定盐酸阿糖胞苷原料药的含量和有关物质

目的:建立同时测定盐酸阿糖胞苷原料药的含量和有关物质的方法。方法:采用超高效液相色谱法。色谱柱为Inertsil ODS-3 C18,流动相为磷酸盐缓冲液-甲醇(梯度洗脱),流速为0.8 ml/min,检测波长为254 nm,柱温为40Ⅴ,进样量为10μl。结果:尿嘧啶、尿苷、阿糖尿苷、盐酸阿糖胞苷检测质量浓度分别在0.100 8²0.16、0.120.16、0.1²0.12、0.095 620.12、0.095 6¹9.12、0.119.12、0.1²0.004μg/ml范围内与各自峰面积积分值呈良好的线性关系(r=0.999 9、0.999 8、0.999 9、0.999 9);精密度、稳定性、重复性试验的RSD≤0.79%;尿嘧啶、尿苷、阿糖尿苷平均加样回收率为103.8%、102.2%、99.7%,RSD分别为2.44%、2.69%、3.16%(n=9)。结论:该方法准确、灵敏度高、专属性强、重复性好,可用于盐酸阿糖胞苷原料药的质量控制。     

mdr1启动子调控CD∷UPP基因对紫杉醇耐药卵巢癌细胞的杀伤作用

目的:探讨腺病毒介导的mdr1启动子调控胞嘧啶脱氨酶∷尿嘧啶磷酸核糖转移酶(CD∷UPP)融合基因联合5-氟胞嘧啶(5-FC)对紫杉醇耐药卵巢癌细胞的特异性杀伤作用。方法:扩增、纯化含有mdr1-CD∷UPP基因的重组腺病毒,转染人卵巢癌紫杉醇耐药细胞株A2780/Taxol和亲本细胞株A2780,RT-PCR检测mdr1和CD∷UPP基因的表达水平;之后加入5-FC,MTT法检测细胞抑制情况及旁观者效应,并观察腺病毒转染后裸鼠移植瘤的生长情况。结果:mdr1和CD∷UPP基因在A2780/Taxol细胞中可稳定表达,转染后A2780/Taxol组的细胞生长明显低于A2780组;转基因的A2780/Taxol细胞联合5-FC后可通过旁观者效应杀伤周围未转基因的耐药细胞;耐药组移植瘤生长明显受到抑制,肿瘤体积为(569.10±187.93)mm3,对照组肿瘤体积为(2111.98±230.82)mm3,差异有统计学意义(P<0.01)。结论:mdr1启动子可调控CD∷UPP基因特异性表达并特异性杀伤紫杉醇耐药卵巢癌细胞。     

1-烷基-5-氨基-6-苯乙基尿嘧啶的合成

研究1-烷基-5-氨基-6-苯乙基尿嘧啶（1a，1b）方便、高产率的合成方法，此类化合物有可能作为非核苷类HIV-1RT抑制剂。以6-甲基尿嘧啶（2）为起始物，经硝化、烷基化、苄基化及一锅反应脱苄基及还原反应等合成目标化合物，并用NMR、MS、IR、Anal鉴定化合物结构。探索出了一种合成1-烷基-5氨基-6-苯乙基尿嘧啶类化合物的方便方法。首次于用3或4步反应、高产率合成了1-烷基-5-氨基-6-苯乙基尿嘧啶（1a，1b）并发现化合物1a有中度抗HIV-1RT的活性（IC50=29μM）。     

Conformationally restrained ceramide analogues: effects of lipophilic modifications on the antiproliferative activity

Conformationally restrained analogues of ceramide containing thiouracil or uracil moieties in their polar head, substituted with an ethyl group in their 6-positions, proved to inhibit cell proliferation and induce apoptosis. A series of new thiouracil and uracil analogues of ceramide possessing several 6-alkyl- or 6-arylalkyl-substituents, were synthesized and tested as inhibitors of cell proliferation. The lipophilic substituents introduced in the 6-position were pure alkyls (n-propyl, n-butyl, i-butyl, neo-pentyl), or aryl-alkyls (2-phenylethyl). Although a significant antiproliferative activity was maintained in most compounds synthesized, none of them showed any improvement with respect to their 6-ethyl-substituted counterparts.     

5种水蛭中尿嘧啶,黄嘌呤,次黄嘌呤的含量比较

采用反相HPLC法测定了宽体金线蛭、光润金线蛭、尖细金线蛭、日本医蛭、菲牛蛭及不同产地的宽体金线蛭中尿嘧啶、黄嘌呤、次黄嘌呤的含量。色谱柱为Shim-pack CLC-ODS C_(18)柱,流动相:0.05mol/l的磷酸氢二铵溶液(pH=8.4),流速:0.8ml/min,检测波长:254nm,回收率:>98.0％。本法准确、快速、重现性好。     

Effect of adsorbed uracil and its derivatives on the rate of oxygen reduction on platinum in acid electrolytes

The rate of oxygen reduction in 0.5 M H₂SO₄ has been controlled by adsorbing uracil and its alkyl derivatives on a Pt electrode. Addition of an ethyl group to C(5), or methyl groups to the C(5) and C(6) positions of uracil, enhances the reaction rate. 5-Ethyluracil and 5,6-dimethyluracil have such an effect, however, only when their concentrations in the electrolyte are ≤0.1 mM. Substitution of the hydrogen on N(3) with CH₃, or exocyclic oxygens with OCH₃ groups results in the inhibition of the reaction; 1,3-dimethyluracil and 2,4-dimethoxypyrimidine (0.1 mM) are two systems that cause inhibition. Interaction between the surface Pt atoms and the N(3) and O sites on the organic molecule, especially in the presence of CH₃ or C₂H₅ groups on the C(5) and/or C(6) centers, are essential for the enhancement. Results of rotating disk electrode experiments suggest that at low overpotentials, 5-ethyluracil and 5,6-dimethyluracil increase the exchange current to produce higher reaction rates.     

HPLC法间接测定肿瘤患者外周血中二氢尿嘧啶脱氢酶的活性

目的:建立间接测定肿瘤患者外周血中二氢尿嘧啶脱氢酶(DPD)活性的方法。方法:采用高效液相色谱(HPLC)法测定肿瘤患者血浆中内源性物质二氢尿嘧啶(H2U)和尿嘧啶(U)的比值,间接估算DPD的活性。其中,色谱柱为XterraRPC18,流动相为甲醇-0.02mol·L-1磷酸二氢钠(pH4.0)(5:95),流速为1.0mL·min-1,检测波长分别为204nm(H2U)、260nm(U)。结果:H2U、U检测浓度分别在62.5～2000μg·L-1(r=0.9997)、15.625～500μg·L-1(r=0.9993)范围内线性关系良好,日内RSD分别≤7.7%、8.3%,日间RSD分别≤13.8%、13.4%,方法回收率分别为99.63%～103.02%、98.38%～109.08%。63例肿瘤患者的DPD活性(H2U/U比值)在肿瘤患者中变异较大,范围为1.51～6.67。结论:本方法可用于肿瘤患者外周血DPD活性的常规监测。