Curcumin ameliorates hepatic chronic inflammation induced by bile duct obstruction in mice through the activation of heme oxygenase-1

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补骨脂素抗增生性瘢痕作用机制研究

目的探讨补骨脂素抗增生性瘢痕的作用机制。方法体外培养成纤维细胞,按随机数字表法分为正常组(培养正常成纤维细胞)、瘢痕组(培养增生性瘢痕成纤维细胞)、TGF-β1组(10 ng/ml TGF-β1处理增生性瘢痕成纤维细胞5 min^12 h)、Smurf2 RNA干扰组[Smad泛素化调节因子2(Smad ubiquitin regulatory factor2,Smurf2)siRNA转染增生性瘢痕成纤维细胞72 h]、补骨脂素组(10μmol/L补骨脂素处理增生性瘢痕成纤维细胞继续培养72 h)、补骨脂素+TGF-β1组(增生性瘢痕成纤维细胞加入补骨脂素培养72 h后加入TGF-β1培养6 h)。采用Western blot法检测Smurf2、α-平滑肌肌动蛋白(α-actin SMA,α-SMA)蛋白表达;RT-PCR法检测Ⅰ型胶原蛋白mRNA表达;ELISA法检测TGF-β1蛋白分泌。结果与正常组比较,瘢痕组Smurf2蛋白[(0.83±0.08)比(0.38±0.07)]表达增加(P<0.05);与瘢痕组比较,Smurf2 RNA干扰组TGF-β1[(2.2±0.18)比(4.2±0.47)]表达降低(P<0.05);TGF-β1组Smurf2[(0.71±0.06)比(0.42±0.04)]、α-SMA[(1.42±0.12)比(0.91±0.09)]蛋白表达增加(P<0.05),Ⅰ型胶原蛋白mRNA[(0.72±0.09)比(0.41±0.07)]表达增加(P<0.05);补骨脂素组Smurf2[(0.05±0.01)比(0.42±0.04)]、α-SMA[(0.71±0.07)比(0.91±0.09)]蛋白表达降低(P<0.05),Ⅰ型胶原蛋白mRNA表达[(0.12±0.04)比(0.41±0.07)]降低(P<0.05)。结论补骨脂素可能通过TGF-β1/Smurf2信号通路抑制α-SMA蛋白表达,从而降低Ⅰ型胶原蛋白表达,起到抑制瘢痕形成的作用。     

Synthesis of TPH-13, a new tridecapeptide from Phyllomedusa rohdei

The synthesis of TPH-13 (Glp-Glu-Lys-Pro-Tyr-Trp-Pro-Pro-Pro-Ile-Tyr-Pro-Met-OH), a tridecapeptide isolated from the skin of the South American frog Phyllomedusa rohdei, is described and alternative approaches are discussed.     

Synthesis and Properties of Haptens for the Development of Radioimmunoassays for Thioridazine,Mesoridazine, and Sulforidazine

For the separate development of radioimmunoassay procedures for thioridazine and its two major active metabolites, mesoridazine and sulforidazine, three haptens, respectively, 2-methylthio-, 2-methylsulfinyl-, and 2-methylsulfonyl-substituted 10-[2-[l-(2-carboxyethyl)-2-piperidinyl]ethyl]-10H-phenothiazine, were synthesized and characterized. Thioridazine hapten was coupled to bovine serum albumin, whereas the haptens for mesoridazine and sulforidazine were coupled to porcine thyroglobulin. The number of hapten residues per mole of carrier protein was determined in each case by an ultraviolet spectrophotometric method. Polyclonal antibodies to each hapten–protein conjugate were obtained in rabbits, and titers of the antisera were checked by evaluating their binding characteristics to the appropriate tritiated analyte. A hapten for the ring sulfoxide metabolite of thioridazine was also synthesized.     

二乙酰二脱水卫矛醇对小鼠白血病L1210细胞增殖的影响

目的　研究二乙酰二脱水卫矛醇 (1 ,2 :5 ,6 dianhydro 3 ,4 diacetylgalactitol,DADAG)的抗脑白血病作用及机制。方法　用小鼠脑内移植瘤模型、MTT法、DNA掺入法、流式细胞仪和Westernblot法 ,观察DADAG对小鼠脑内移植瘤和体外白血病L1 2 1 0 细胞的作用 ,并探讨作用机制。结果　DADAG对DBA/ 2小鼠脑内移植白血病L1 2 1 0 有明显的抑制作用 ;对体外白血病L1 2 1 0 细胞同样有很强的抗增殖作用 ,其IC50 值为 2 4 6mg·L- 1 。DADAG不可逆地抑制L1 2 1 0 细胞内DNA的生物合成。DADAG 2 4mg·L- 1 处理L1 2 1 0 细胞 6h后 ,细胞发生G2 /M周期阻滞 ,2 4h后达最高峰。细胞周期素B1 蛋白水平在DADAG处理 2 4h后开始下降 ,而磷酸化的细胞周期依赖性激酶CDK1在DADAG处理 6h后开始上调 ,并呈时间依赖性。结论　DADAG的抗脑白血病作用与其抑制白血病细胞的增殖密切相关     

稳定性核素测定大鼠小肠蛋白质合成

目的：建立稳定性核素（[L-^15N]亮氨酸）测定大鼠小肠蛋白质合成率的方法。方法：分别测定静脉注射相同剂量[L-^15N]亮氨酸不同时相的大鼠小肠^15N丰度及不同剂量[L-^15N]亮氨酸同一时相的大鼠小肠^15N丰度。结果：大鼠小肠游离氨基酸池中^15N核素丰度在注射后0．5h内呈线性上升并达高峰，维持4h后缓慢下降，小肠蛋白质中的^15N丰度0．5h至12h基本维持不变；随着注射剂量的增加，大鼠小肠蛋白质分数合成率（FSR）亦增加，当[L-^15N]亮氨酸剂量在1．0mmol／kg以上，FSR并不随施加[L15N]亮氨酸剂量的加大而增加。结论：在进行大鼠小肠蛋白质合成率测定时，一次性静脉注射的测量最佳时限为0．5h，剂量为1．0mmol／kg。     

骨胶原与骨质疏松骨密度及骨生物力学的相关性研究

目的探讨骨胶原含量在绝经后骨质疏松症的发生、发展及在骨质疏松性骨折中的作用。方法取7个月龄未交配雌性SD大鼠60只，随机分为四组，A组：对照组（sham组）；B组：切除卵巢组；C组：切除卵巢＋雌激素治疗组；D组：切除卵巢＋降钙素治疗组。除A组外，其他三组通过切除双侧卵巢法12周后制成骨质疏松模型，24周后分别行k的力学特性、右侧股骨三点弯曲试验、羟脯氨酸含量、k骨密度（BMD）测定，Masson三色染色法显示骨胶原形态。结果A、C、D组与B组在k羟脯氨酸含量、BMD、k压缩力学参数值、右侧股骨生物力学参数值、骨胶原染色含量及形态方面差异均有统计学意义（P〈0．05），而A、C、D组之间差异无统计学意义（P〉0．05）。统计学分析显示羟脯氨酸含量与BMD及骨生物力学参数值呈直线相关性。结论骨质疏松的发生与骨胶原含量下降有关。骨胶原含量的下降与BMD降低及骨生物力学改变呈相关性。应用雌激素和降钙素治疗去势后骨质疏松大鼠，不仅可以提高其BMD含量和骨生物力学性能，而且还可以提高骨胶原的含量。     

胶原蛋白-明胶支架材料修复大鼠坐骨神经缺损的研究

目的制备胶原蛋白一明胶神经支架材料（CG材料）并研究其在修复大鼠10mm坐骨神经缺损实验中的疗效。方法以I型胶原蛋白、明胶通过冷冻干燥技术制备具有轴向微管结构的神经支架材料，用其桥接修复sD大鼠坐骨神经10mm缺损。术后16周分别行透射电镜，S-100、β-tubulin class Ⅲ、NFl60免疫荧光染色以及电生理检测，观察支架材料引导神经再生的疗效。结果制备的材料内部为孔径均匀且平行排列的微管结构，术后16周通过透射电镜和免疫荧光染色可见大量再生神经纤维，电生理检测神经传导速度及波幅接近自体神经移植。结论胶原蛋白一明胶支架材料能够有效的促进周围神经再生。     

Hemolytic properties and riboflavin synthesis of Helicobacter pylori: cloning and functional characterization of the ribA gene encoding GTP-cyclohydrolase II that confers hemolytic activity to Escherichia coli

Various strains of Helicobacter pylori were able to lyse erythrocytes from sheep, horse, and human when grown on blood agar. The hemolysis did not depend on the production of the vacuolating cytotoxin VacA as demonstrated by the hemolytic behavior of an isogenic vacA-negative mutant strain. The hemolytic activity could be detected in cell-free supernatants and was not regulated by iron. To isolate genes coding for proteins involved in the destruction of erythrocytes, a plasmid-based DNA library was screened for expression of lytic activity on blood agar. This approach revealed that the H. pylori ribA gene confers hemolytic properties to Escherichia coli. The ribA gene encodes the enzyme GTP-cyclohydrolase II [EC 3.5.4.25] that catalyzes the initial step in the synthesis of riboflavin. The predicted amino acid sequence of the H. pylori RibA protein showed a high degree of similarity to equivalent enzymes from microorganisms and from plants. The single gene on a plasmid restored riboflavin synthesis in a ribA mutant of E. coli and induced hemolytic activity. Furthermore, ribA overexpression was associated with the production of a fluorescent yellow molecule that was not identical with riboflavin. Hemolysis was also seen for the ribA gene from E. coli, indicating that this feature was not specific for the H. pylori gene. The presence of ribA in various H. pylori strains was confirmed by Southern blot hybridization and by polymerase chain reaction with specific primers. This analysis revealed that microdiversity exists within the DNA region upstream from ribA, which was further confirmed by nucleotide sequence analysis. Received: 25 July 1997     

The 2,4-dinitrophenyl group for protection of hydroxyl function of tyrosine during solid-phase peptide synthesis

The facile thiolytic cleavage of the O-2,4-dinitrophenyl (Dnp) tyrosine bond was applied to the solid-phase synthesis of the 22-amino acid residue peptide H-Asp-Ala-Val-Tyr -Thr-Gly-Leu-Asn-Thr-Arg-Asn-Gln-Glu-Thr-Tyr -Glu-Thr-Leu-Lys-His-Glu-Lys-OH, corresponding to positions 62-83 in the chain of the type 1 receptor for Fc_ε, domains expressed on the rat mucosal-type mast cells (line RBL-2H3). A method for the spectrophotometric determination of insoluble O-Dnp as well as of unprotected phenolic moieties of tyrosine was developed. It is based on monitoring S-Dnp-2-mercaptoethanol, produced upon O-Dnp thiolysis by 2-mercaptoethanol. © Munksgaard 1995. Dedicated to the memory of Dr. Susumu Funakoshi, a dear friend and a leader in peptide chemistry.