小剂量普通肝素治疗重度慢性乙型病毒性肝炎临床研究

目的研究小剂量普通肝素治疗重度慢性乙型肝炎的疗效和安全性。方法将70例重度慢性乙型肝炎患者分为三组,对照组25例予常规护肝退黄抗病毒治疗(甘利欣、苦黄、水溶性维生素、拉米夫定等);腺苷蛋氨酸组20例在对照组治疗基础上,加用腺苷蛋氨酸1000mg加入0.9%生理盐水250ml中静脉滴注,1次/d,10d为一个疗程;肝素组25例在对照组治疗基础上,加用普通肝素钠25mg加入0.9%生理盐水250ml中静脉滴注,1次/d,10d为一个疗程;观察治疗前后患者的血清谷丙转氨酶、胆红素、凝血酶原时间的变化。结果肝素组在重度慢性乙型肝炎的血清谷丙转氨酶、胆红素、凝血酶原时间恢复方面,明显优于对照组(P<0.05),与腺苷蛋氨酸组疗效相近,但肝素组所用费用较腺苷蛋氨酸组低。结论小剂量普通肝素对重度慢性乙型肝炎有明显疗效,且费用低,临床应用安全。     

人鸟氨酸脱羧酶和S-腺苷甲硫氨酸脱羧酶双反义腺病毒载体的构建

目的：构建人鸟氨酸脱羧酶(ODC)第三外显子和S-腺苷甲硫氨酸脱羧酶(SAMDC)翻译起始位点双反义RNA腺病毒载体。方法：应用RT-PCR方法扩增出SAMDC mRNA翻译起始位点区205 bp的基因片断。插入PMD-18T载体中．经XbaI、XhoI酶切回收,反向插入穿梭质粒pAdTrack-CMV-ODCr,形成重组质粒pAdTrack-ODC-SAMDCr。经PmeI酶切线性化后,转入Adeasy-1细菌与pAdeasy-1质粒发生同源重组。挑选阳性重组质粒pAdeasy-ODC-SAMDCr,经PacI酶切后,转染293细胞,包装出腺病毒颗粒．经荧光显微镜和PCR方法对重组腺病毒进行鉴定。结果：利用RT-PCR方法成功地从大肠癌细胞扩增出205bp的cDNA片断,经测序证实为SAMDC翻译起始位点序列。测序证实,重组质粒pAdTrack-ODC-SAMDCr两个基因插入方向和序列均正确．转入Adeasy-1细菌获得多个阳性重组克隆。pAdeasy-ODC-SAMDCr转染293细胞进行包装扩增．可见明显病毒空斑形成,荧光显微镜下可见绿色荧光蛋白在293细胞中表达．PCR法证实含有目的基因。结论：成功构建并扩增出ODC和SAMDC双反义RNA腺病毒载体．为以后肿瘤的基因治疗和预防研究提供了必要工具。     

鸟氨酸脱羧酶和S-腺苷甲硫氨酸脱羧酶双反义腺病毒对大肠癌细胞生长的抑制作用

目的：研究鸟氨酸脱羧酶（ODC）和S-腺苷甲硫氨酸脱羧酶（AdoMetDC）双反义腺病毒（Ad—ODC—AdoMetDCas）对大肠癌细胞生长的抑制作用，并初步探讨其参与细胞周期调节的分子机制。方法：将Ad—ODC—AdoMetDCas感染大肠癌细胞株HT-29，通过MTS法观察其对HT-29细胞增殖的影响，流式细胞术检测其对细胞周期的影响，采用Western blot检测Ad—ODC—AdoMetDCas对细胞中ODC、AdoMetDC及细胞周期调节蛋白（Cyclin D1 and CDK4）的表达的影响，利用EBRT—PCR检测Ad—ODC—AdoMetDCas对细胞周期蛋白Cyclin D1的mRNA水平的影响。结果：Ad—ODC—AdoMetDCas可抑制HT-29细胞中ODC和AdoMetDC蛋白的表达，并可明显抑制细胞的增殖，引起细胞周期GI期阻滞，抑制G，期主要的细胞周期蛋白Cyclin D1的转录和翻译。结论：Ad—ODC—AdoMetDCas可有效下调ODC和AdoMetDC的表达，并通过抑制Cyclin D1的表达使其细胞周期停滞于G1期，从而抑制大肠癌细胞HT-29的增殖，为进一步研究大肠癌的基因治疗打下基     

Prostate specific antigen promoter-driven adenovirus-mediated expression of both ODC and AdoMetDC antisenses inhibit prostate cancer growth

Objective  

To generate recombinant adenovirus that could simultaneously express ornithine decarboxylase (ODC) and S-adenosylmethionine decarboxylase (AdoMetDC) antisenses specifically in prostate cancer cells, and evaluate its inhibitory effect on prostate cancer in vivo.     

Identification of an S-adenosylmethionine (SAM) dependent arsenic methyltransferase in Danio rerio

Arsenic methylation is an important cellular metabolic process that modulates arsenic toxicity and carcinogenicity. Biomethylation of arsenic produces a series of mono-, di- and tri-methylated arsenic metabolites that can be detected in tissues and excretions. Here we report that zebrafish exposed to arsenite (As^III) produces organic arsenicals, including MMA^III, MMA^V and DMA^V with characteristic tissue ratios, demonstrating that an arsenic methylation pathway exists in zebrafish. In mammals, cellular inorganic arsenic is methylated by a SAM-dependent arsenic methyltransferase, AS3MT. A zebrafish arsenic methyltransferase homolog, As3mt, was identified by sequence alignment. Western blotting analysis showed that As3mt was universally expressed in zebrafish tissues. Prominent expression in liver and intestine correlated with methylated arsenic metabolites detected in those tissues. As3mt was expressed in and purified from Escherichia coli for in vitro functional studies. Our results demonstrated that As3mt methylated As^III to DMA^V as an end product and produced MMA^III and MMA^V as intermediates. The activity of As3mt was inhibited by elevated concentrations of the substrate As^III as well as the metalloid selenite, which is a well-known antagonistic micronutrient of arsenic toxicity. The activity As3mt was abolished by substitution of either Cys160 or Cys210, which corresponds to conserved cysteine residues in AS3MT homologs, suggesting that they are involved in catalysis. Expression in zebrafish of an enzyme that has a similar function to human and rodent orthologs in catalyzing intracellular arsenic biomethylation validates the applicability of zebrafish as a valuable vertebrate model for understanding arsenic-associated diseases in humans.     

腺苷蛋氨酸联合苦参碱治疗病毒性肝炎高胆红素血症60例

目的观察腺苷蛋氨酸联合苦参碱治疗病毒性肝炎高胆红素血症的临床疗效。方法将病毒性肝炎高胆红素血症患者120例随机均分为治疗组和对照组,对照组采用保肝、降酶等对症支持治疗,治疗组在对照组治疗基础上加用腺苷蛋氨酸1 000 mg加入5%葡萄糖注射液250 mL中静脉滴注,1次/d,苦参碱注射液250 mL静脉滴注,1次/d。观察两组患者治疗前后肝功能和凝血功能的变化。结果治疗组治疗后血清总胆红素和凝血酶原时间下降幅度明显大于对照组(P<0.01)。结论腺苷蛋氨酸联合苦参碱能明显改善病毒性肝炎高胆红素血症患者的肝功能,降低血清胆红素,缩短凝血酶原时间,疗效显著,值得临床推广。     

思美泰治疗妊娠肝内胆汁淤积症的临床观察

目的 探讨思美泰治疗妊娠肝人胆汁淤积症（ICP）的临床效果。方法 采用思美泰治疗60例ICP患者，治疗前后测定血清甘胆酸（CG）和肝功能。治疗组妊娠结局与同期未经治疗的120例ICP患者作对照。结果 治疗前后比较，血清CG、ALT、AST有显著性下降（P＜0．01），瘙痒症状减轻，黄疸消退。治疗组羊水污染发生率、胎儿窘迫发生率均明显低于对照组（P＜0．05）。未发现药物对母儿的不良反应。结论 思美泰治疗ICP安全有效，值得临床推广。     

低分子肝素和S-腺苷蛋氨酸治疗妊娠期肝内胆汁淤积症的疗效对比

目的:比较和评估低分子肝素(LMWH)和S-腺苷蛋氨酸(SAMe)对妊娠期肝内胆汁淤积症(ICP)的治疗效果。方法:64例ICP患者,随机分成两组:A组用LMWH 1250 IU/d静脉滴注,5天为1疗程;B组用SAMe 1 000 mg/d,静脉滴注,疗程为7天,观察治疗效果。结果:两组患者治疗后瘙痒评分、血清总胆汁酸(TBA)、丙氨酸氨基转移酶(ALT)、天冬氨酸氨基转移酶(AST)、总胆红素(TB)及直接胆红素(DB)均有明显下降(P<0.05),下降程度两组间无统计学差异(P>0.05);两组间早产、羊水Ⅱ°～Ⅲ°粪染、胎儿窘迫、新生儿窒息(Apgar≤7)的发生率无明显差异;A组无围生儿死亡,B组有1例死胎。结论:LMWH能缓解ICP患者的症状,改善肝功能,其治疗作用与SAMe相似。     

NO sensitizes rat hepatocytes to proliferation by modifying S-adenosylmethionine levels

BACKGROUND & AIMS: Liver regeneration is a fundamental response of this organ to injury. Hepatocyte proliferation is triggered by growth factors, such as hepatocyte growth factor. However, hepatocytes need to be primed to react to mitogenic signals. It is known that nitrous oxide (NO), generated after partial hepatectomy, plays an important role in hepatocyte growth. Nevertheless, the molecular mechanisms behind this priming event are not completely known. S-adenosylmethionine (AdoMet) synthesis by methionine adenosyltransferase is the first step in methionine metabolism, and NO regulates hepatocyte S-adenosylmethionine levels through specific inhibition of this enzyme. We have studied the modulation of hepatocyte growth factor-induced proliferation by NO through the regulation of S-adenosylmethionine levels. METHODS: Studies were conducted in cultured rat hepatocytes isolated by collagenase perfusion, which triggers NO synthesis. RESULTS: The mitogenic response to hepatocyte growth factor was blunted when inducible NO synthase was inhibited; this process was overcome by the addition of an NO donor. This effect was dependent on methionine concentration in culture medium and intracellular S-adenosylmethionine levels. Accordingly, we found that S-adenosylmethionine inhibits hepatocyte growth factor-induced cyclin D1 and D2 expression, activator protein 1 induction, and hepatocyte proliferation. CONCLUSIONS: Together our findings indicate that NO may switch hepatocytes into a hepatocyte growth factor-responsive state through the down-regulation of S-adenosylmethionine levels.