MTHFR多态性对晚期胃癌患者化疗作用的预测研究

目的:研究亚甲基四氢叶酸还原酶(MTHFR)基因C677T、A1298C多态与胃癌患者对5-FU为基础的化疗敏感性和毒性的关系。方法:晚期胃癌患者106例,用聚合酶链反应-限定性片段长度多态性(PCR-RFLP)技术检测白细胞DNAMTH-FR基因型。所有患者经5-FU为基础的化疗方案治疗。结果:1)在106例晚期胃癌患者中,MTHFRC677TCC、CT、TT基因型分别占31·1%、46·2%和22·6%;MTH-FRA1298CAA、AC、CC基因型者分别为69·8%、29·2%和0·9%;化疗总有效率35·8%。2)MTHFRC677TTT基因型携带者化疗有效率(83·3%)明显高于C677TCT(24·5%;P=0·000)和C677TCC(18·2%;P=0·000)。而MTHFRA1298CAA组有效率(43·2%)亦明显高于A1298CAC CC组(18·8%,P=0·009)。3)在CFL、CFH、LFP方案治疗的患者中,C677T变异子携带者对化疗敏感性更高。对A1298C多态性,患者接受CFL方案化疗时,1298AA纯合子携带者有效率高于1298CT/CC患者。4)MTHFRC677TTT、CT或A1298CAA多态性携带者化疗相关的恶心/呕吐发生率明显高于其他三种多态性者。结论:MTHFR基因多态性的检测可能是晚期胃癌患者接受5-FU为基础化疗疗效和毒副反应的良好预测指标。     

红细胞醛糖还原酶测定荧光法的建立及临床应用

红细胞醛糖还原酶测定荧光法的实验探讨。方法利用ＮＡＤＰＨ、ＤＬ－甘油醛 ,磷酸缓冲液和适量红细胞溶血液组成的反应体系,建立了一种红细胞醛糖还原酶的荧光测定法,并对酶反应最适条件进行了实验探讨。     

Normobaric hyperoxia plays a neuroprotective role after cerebral ischemia by maintaining the redox homeostasis and the level of connexin43 in astrocytes

IntroductionAcute cerebral ischemia is caused by an insufficient blood supply to brain tissue. Oxygen therapy, which is able to aid diffusion to reach the ischemic region, has been regarded as a possible treatment for cerebral ischemia. Recent animal and pilot clinical studies have reported that normobaric hyperoxia (NBO) showed neuroprotective effects if started soon after the onset of stroke. However, little is known about the role and mechanism of NBO treatment in astrocytes. Connexin43, one of the main gap junction proteins in astrocytes, is extremely sensitive to hypoxia and oxidative stress after cerebral ischemia.AimsIn the present study, we used sutures to develop an ischemia/reperfusion model in rats to mimic clinical recanalization and investigated the role of connexin43 in NBO‐treated stroke rats, as well as the underlying mechanism of NBO therapy.ResultsNormobaric hyperoxia treatment maintained the homeostasis of oxidoreductases: glutathione peroxidase 4 (GPX4) and NADPH oxidase 4 (two important oxidoreductases) and rescued the ischemia/reperfusion‐induced downregulation of connexin43 protein in astrocytes. Furthermore, NBO treatment attenuated cerebral ischemia‐induced cytochrome c release from mitochondria and was involved in neuroprotective effects by regulating the GPX4 and connexin43 pathway, using Ferrostatin‐1 (an activator of GPX4) or Gap27 (an inhibitor of connexin43).ConclusionsThis study showed the neuroprotective effects of NBO treatment by reducing oxidative stress and maintaining the level of connexin43 in astrocytes, which could be used for the clinical treatment of ischemic stroke.     

肝苏颗粒联合还原型谷胱甘肽或美能片治疗慢性乙型肝炎的疗效评价

目的 观察评价肝苏颗粒联合还原型谷胱甘肽或联合美能片治疗慢性乙型肝炎的临床疗效.方法 将160例慢性乙型肝炎患者随机分为治疗Ⅰ组55例、治疗Ⅱ组55例、对照组50例.治疗Ⅰ组口服肝苏颗粒并静脉滴注还原型谷胱甘肽,治疗Ⅱ组口服肝苏颗粒和美能片,对照组采用常规保肝治疗,疗程均为3个月.结果治疗Ⅰ组、治疗Ⅱ组肝功能指标、乙型肝炎病毒血清标志物改善情况优于对照组(P ＜ 0.01),症状改善和临床有效率均优于对照组(P ＜ 0.05),但治疗Ⅰ组与治疗Ⅱ组比较则无明显差异(P ＞ 0.05).结论 肝苏颗粒与还原型谷胱甘肽或与美能片联用治疗慢性乙型肝炎,在降酶、退黄、促进肝功能恢复以及改善临床症状方面都有满意疗效.     

糖尿病肾病病人醛糖还原酶基因多态性相关研究

目的探讨醛糖还原酶（AR）基因5’端（AC）n多态性与2型糖尿病肾病的关系。方法采用聚合酶链反应（PCR）、聚丙烯酰胺凝胶电泳及银染色技术分析了139例2型糖尿病病人（早期糖尿病肾病组61例,非糖尿病肾病组78例）和63例正常对照者AR基因5’端（AC）n的多态性。结果早期糖尿病肾病组Z-2等位基因频率高于非糖尿病肾病组和正常对照组（x^2=6．88、10．51,P〈0．01）;含Z～2等位基因的基因型频率也高于非糖尿病肾病组和正常对照组（X^2=4．95、8．15,P〈0．05、0．01）。结论AR基因Z-2等位基因与青岛地区汉族2型糖尿病病人糖尿病肾病的发生发展有关。     

中草药来源的醛糖还原酶抑制剂的研究进展

中草药作为天然产物,无明显不良反应且来源广泛,以中草药为来源的醛糖还原酶抑制剂其不良反应远低于化学合成及微生物来源的醛糖还原酶抑制剂,在有效阻止和延缓糖尿病并发症如:糖尿病肾病、血管病变、视网膜病变、外周神经病变方面显示了良好的应用前景。作者主要综述了中草药活性成分黄酮类化合物及其衍生物,如:槲皮素、水飞蓟素、葛根素、黄芩苷、黄连素等和一些中药复方制剂,如:参丹健胰丸、筋脉通、六味地黄丸等在抑制醛糖还原酶的活性、降低山梨醇含量等方面取得的研究进展,并对其在治疗糖尿病并发症方面的现状进行了阐述。     

三七3-羟基-3-甲基戊二酸单酰辅酶A还原酶基因的克隆和生物信息学分析

目的克隆三七总皂苷甲羟戊酸合成途径中的1个关键酶3-羟基-3-甲基戊二酸单酰辅酶A还原酶(3-hydroxy-3-methylglutaryl coenzyme-A reductase,HMGR)基因,为进一步研究HMGR蛋白的功能及开展三七皂苷的合成生物学研究奠定基础。方法根据NCBI上已公布的同属人参的HMGR基因全长序列(登录号GU565097.1)设计特异性引物。利用RT-PCR技术,以三七愈伤组织总RNA反转录的cDNA为模板扩增基因片段;并对其编码的蛋白进行生物信息学预测和基因表达分析。结果序列分析表明,获得的三七HMGR(命名为PnHMGR)基因的cDNA序列大小为1 893 bp,该序列与人参、刺五加和杜仲中HMGR基因的一致性分别达到98%、93%、80%,且含有大小为1 725 bp的开放阅读框,经Genbank查询为一新的cDNA。生物信息学预测PnHMGR基因编码蛋白包含2个跨膜区,不含信号肽,具有HMGR催化作用的活性中心结构域。实时荧光定量PCR检测到PnHMGR基因在三七细胞生长30 d表达量最高。结论首次从药用植物三七中克隆得到HMGR基因的编码区序列,为进一步鉴定PnHMGR的功能和开展三七皂苷的合成生物学研究奠定了基础。     

二烯丙基二硫对小鼠肾包膜下移植人胃癌细胞的生长抑制作用

二烯丙基二硫(diallyl disulfide,DADS)是大蒜的主要有效成分,对多种肿瘤均有明显的抑制作用[1].本室体外研究表明:DADS可明显抑制人胃癌MGC803细胞生长[2],其机制与G2/M期阻滞和信号传导通路ERK/AP-1途径有关[3,4].本研究采用人肿瘤细胞肾包膜下移植模型,探讨DADS对体内生长的MGC803细胞的抑制作用.     

Polymorphisms of human cytochrome P450 2C9 and the functional relevance

Human cytochrome P450 2C9 (CYP2C9) accounts for ∼20% of hepatic total CYP content and metabolizes ∼15% clinical drugs such as phenytoin, S-warfarin, tolbutamide, losartan, and many nonsteroidal anti-inflammatory agents (NSAIDs). CYP2C9 is highly polymorphic, with at least 33 variants of CYP2C9 (*1B through *34) being identified so far. CYP2C9*2 is frequent among Caucasians with ∼1% of the population being homozygous carriers and 22% are heterozygous. The corresponding figures for the CYP2C9*3 allele are 0.4% and 15%, respectively. There are a number of clinical studies addressing the impact of CYP2C9 polymorphisms on the clearance and/or therapeutic response of therapeutic drugs. These studies have highlighted the importance of the CYP2C9*2 and *3 alleles as a determining factor for drug clearance and drug response. The CYP2C9 polymorphisms are relevant for the efficacy and adverse effects of numerous NSAIDs, sulfonylurea antidiabetic drugs and, most critically, oral anticoagulants belonging to the class of vitamin K epoxide reductase inhibitors. Warfarin has served as a practical example of how pharmacogenetics can be utilized to achieve maximum efficacy and minimum toxicity. For many of these drugs, a clear gene–dose and gene–effect relationship has been observed in patients. In this regard, CYP2C9 alleles can be considered as a useful biomarker in monitoring drug response and adverse effects. Genetic testing of CYP2C9 is expected to play a role in predicting drug clearance and conducting individualized pharmacotherapy. However, prospective clinical studies with large samples are warranted to establish gene–dose and gene–effect relationships for CYP2C9 and its substrate drugs.     

氨基酸和酵母膏对谷胱甘肽发酵的影响

研究了氨基酸和酵母膏对酵母发酵生产谷胱甘肽（ＧＳＨ）的影响。结果表明，多种氨基酸能促进酵母的生长，对ＧＳＨ的生物合成却没有明显促进作用，而半胱氨酸则表现为在抑制酵母生长的同时显著提高胞内ＧＳＨ含量。半胱氨酸初始浓度为５ｍｍｏｌ／Ｌ时ＧＳＨ比产生速率最大，为３．７ｍｇ·ｇｃｅｌ－１·ｈ－１。酵母膏对酵母的生长和ＧＳＨ的合成均有显著的促进作用。若不添加酵母膏，则３％糖浓度下胞内ＧＳＨ含量只有１％糖浓度下的５０％；而若在３％和１％糖浓度下分别添加０．６％的酵母膏，前者胞内ＧＳＨ含量比不加酵母膏的对照提高了一倍左右；３％糖浓度（补糖操作）发酵液中ＧＳＨ总量（９２．５ｍｇ／Ｌ）比１％糖浓度的ＧＳＨ总量高４８％。