慢性乙型肝炎病毒感染者转化生长因子-β1基因单核苷酸多态性分析

目的 探讨转化生长因子(TGF)-β1单核苷酸多态性(SNP)与慢性HBV感染的关系.方法 采用PCR方法,对74例慢性乙型肝炎患者、41例乙型肝炎肝硬化患者和41例健康人外周血细胞基因组DNA的TGF-β1基因中三个SNP位点(rs2241715、rs2241716、rs4803455)进行基因分型.数据分析采用χ2或Fisher精确概率法检验.结果 健康人的 rs2241715基因型及等位基因频率与慢性乙型肝炎和肝硬化患者相比,差异有统计学意义(χ2=11.419,P＜0.01或χ2=6.218χ2=5.961;P＜0.05),rs2241715 T/T基因型的个体患慢性乙型肝炎和乙型肝炎肝硬化的相对危险度分别为其他型的2.974倍(95%CI=1.209～7.314,P=0.018)和3.228倍(95%CI=1.201～8.675,P=0.020),rs2241716和rs4803455位点则无上述相关性.结论 TGF-131基因的rs2241715 SNP位点T/T基因型可能与慢性HBV感染密切相关.     

体质量指数和L型钙离子通道α1C基因多态性对小剂量氨氯地平降压疗效的交互作用

目的研究体质量指数(BMI)和L型钙离子通道α1C基因(CACNA1C)单核苷酸多态性(SNP)对小剂量氨氯地平降压疗效的交互作用。方法采用PCR直接测序法对服用以氨氯地平为主要降压药物的原发性高血压患者181例的CACNA1C基因SNPrs1051375、rs2238032、rs2239050、rs2239128等位点进行基因分型。采用多因素方差分析和有序Logistic回归方法分析BMI和SNP对降压疗效的交互作用。结果经多元线性回归方法调整基线血压、年龄、性别、尿酸、三酰甘油、药物等因素后,BMI和rs2238032G/T位点与用药后收缩压降幅均相关(B=-0.612,P=0.044;B=11.818,P=0.037),rs2238032G/T位点与用药后舒张压降幅亦相关(B=12.450,P=0.001)。多因素方差分析显示rs2238032G/T位点基因型与BMI存在交互作用(P<0.05),携带rs2238032G/T位点TT基因型和BMI正常(<25kg/m2)患者对氨氯地平的降压疗效高于携带GT和GG基因型的超重患者。有序Logistic回归分析亦显示出rs2238032G/T位点GT基因型与BMI存在交互作用的趋势(B=0.212,P=0.066)。结论 BMI和CACNA1C基因rs2238032G/T位点基因型对小剂量氨氯地平的降压疗效可能存在交互作用。     

补体C5基因单核苷酸多态性与肝细胞癌易感性关系的研究

目的探讨中国华北地区乙型肝炎患者补体C5单核苷酸多态性(single-nucleotide polymorphisms,SNP)与肝细胞癌(hepatocellular carcinoma,HCC)易感性的关系。方法采用Mass ARRAY TM Analyzer技术平台进行C5 rs17611、rs25681及rs2300929 3个SNP的多态性基因型检测,并进行风险度分析、连锁不平衡及单倍型分析,探讨3个SNP与HCC易感性的关系。结果与对照组比较,HCC组中rs17611位点等位基因G、rs25681位点等位基因C及rs2300929位点等位基因C可明显增加HCC的发病风险[P0.05,OR(95%CI)1];单体型为rs17611G-rs25681C-rs2300929C可增加HCC发病风险(OR=3.708,95%CI:1.578~8.712),单体型为rs17611A-rs25681T-rs2300929T可减少HCC的发病风险(OR=0.525,95%CI:0.303~0.909)。结论 C5rs17611、rs25681及rs2300929 3个位点的基因多态性与HCC易感性有关,可作为筛查HCC好发的危险因素。     

GABAA受体基因多态性与癫痫易感性的关系

目的探究γ-氨基丁酸A型(GABAA)受体的亚基基因GABRG2和GABRB2单核苷酸多态性(SNP)与癫痫(EP)易感性的关系。方法应用限制性片段长度多态性(RFLP)技术对GABAA受体亚基基因GABRB2(rs12653921、rs2964773)、GABRG2(rs2268581)3个标签单核苷酸多态性(Tag SNP)的等位基因和基因型测定分析。结果 EP组和对照组等位基因频率和基因型分布比较,SNP(rs12653921)位点(基因型χ2=8.651,等位基因χ2=8.649)有统计学意义;SNP(rs2268581)、SNP(rs2964773)位点(rs2268581:基因型χ2=0.354,等位基因χ2=0.294;rs2964773:基因型χ2=1.397,等位基因χ2=0.643)无显著差异(P0.05)。结论 SNP(rs12653921)可能与EP易感性相关,SNP(rs2268581)、SNP(rs2964773)可能与EP易感性不相关。     

BTLA基因多态性与慢性HBV感染家系的遗传易感性

目的:探讨中国汉族人群T、B淋巴细胞弱化因子(Band Tlymphocyte attenuator,BTLA)基因单核苷酸多态性(single nucleotide polymorphism,SNP)与慢性乙型肝炎病毒(hepatitis Bvirus,HBV)感染家系的遗传易感性.方法:采用SNaPshot技术检测核心家系中慢性HBV感染者及其家庭成员BTLA基因rs2633562和rs2952323 SNP位点的多态性,采用家系内关联性分析(family-based association test,FBAT)基因型、等位基因及单体型分布频率.结果:单位点S N P遗传关联性分析显示,BTLA基因rs2952323位点多态性与慢性HBV感染的遗传易感有显著的相关性,G/G基因型Z=2.731,P=0.006308,G等位基因在附加遗传模型中Z=2.689,P=0.0007174,隐性遗传模型中Z=2.731,P=0.006308.传统的传递不平衡检验(transmission/disequilibrium test,TDT)和同胞对传递不平衡检验(siblings disequilibrium test,SDT)分析显示无主要的优势等位基因A、C或G从杂合的父母传递给患病子女,P=1.000000,P=0.151590.FBAT单倍型分析结果显示rs2633562-A/rs2952323-G(70.0%)存在优势单倍型传递给患病子女或者患病同胞,在附加遗传模型Z=3.093,P=0.001979,隐性遗传模型中Z=2.825,P=0.004721.结论:BTLA基因位点多态性可能与家族聚集性慢性HBV感染的遗传易感性相关.     

TBX1基因与人类圆锥动脉干畸形相关性的研究

目的在TBX1基因内选取2个已知单核苷酸多态(SNP)G2857C(rs737868)和G2963A(rs28649236),检测其在圆锥动脉干畸形患者和正常人群中的表达情况,分析TBX1基因与圆锥动脉干畸形的相关性。方法2004年3月至2006年5月沈阳军区总医院应用聚合酶链反应-限制性片段长度多态性(PCR-RFLP)方法分析100例圆锥动脉干畸形患者及100名正常人2个SNP位点基因型;应用列联表法统计分析病例组和对照组各SNP位点基因型及等位基因频率。结果G2963A位点等位基因频率及基因型频率在病例组和对照组中的分布差异有显著性,病例组G等位基因频率明显高于对照组(χ2=5.30,P<0.05)。结论TBX1基因编码区的SNP位点G2963A与人类圆锥动脉干畸形有明显的相关性,具有G等位基因的人发生圆锥动脉干畸形的危险性相对增高。     

IL-28B基因多态性与丙型肝炎易感性的关系

目的:探讨白介素-28B(interleukin-28B,IL-28B)单核苷酸多态性位点rs8099917与中国丙型肝炎易感性的关系.方法:采用TaqMan SNP基因分型的方法检测中国天津地区263名丙型肝炎患者和244名健康人IL-28B rs8099917基因型和等位基因分布情况,并统计分析rs8099917基因型和等位基因在2组中分布的差异.结果:在263名丙型肝炎患者中,TT基因型223人(84.8%),TG基因型39人(14.8%),GG基因型1人(0.4%).T等位基因频率为92.2%.244名健康对照者中,TT基因型222人(91.0%),TG21人(8.60%),GG1人(0.40%),T等位基因频率为95.3%.丙型肝炎患者和健康人群TG/GG基因型频率差异有统计学意义(OR=1.810,95%CI:1.042-3.145;P=0.033).丙型肝炎患者G等位基因频率也高于健康人(OR=1.709,95%CI:1.010-2.893;P=0.044).结论:中国人群IL-28B rs8099917基因多态性与丙型肝炎病毒(hepatitis C virus,HCV)感染易感性相关联.G为HCV感染的风险等位基因.     

褪黑色素受体1B基因多态性与妊娠期糖尿病的相关性研究

目的探讨我国褪黑色素受体1B(MTNR1B)基因SNP位点rs10830963和rs1387153的多态性与妊娠期糖尿病(GDM)遗传易感性的关系。方法采用病例对照研究,分别选取GDM患者(GDM组)184例和对照(NC)组235名,利用PCR-RFLP的方法测定2个SNP位点多态性分布,并进行统计学分析。结果 GDM组FPG高于NC组(P=0.039),但孕前BMI比较差异无统计学意义。SNP位点rs10830963基因型(GG,GC,CC)频率、等位基因频率与NC组比较,差异均无统计学意义(P=0.637,P=0.422)。而SNP位点rs1387153基因型(TT,CT,CC)与NC组比较,差异有统计学意义(P=0.012),且风险基因型TT的频率高于NC组(TTvs TC+CC,P=0.01)。GDM组T等位基因高于NC组(OR:1.517,95%CI:1.147~2.006,P=0.003),且该SNP位点的TT基因型的GDM患者FPG高于其他两个基因型的患者。结论 MTNR1B基因SNP位点rs10830963与GDM无相关性,而SNP位点rs1387153与GDM的易感性相关。     

mTOR基因多态性与2型糖尿病及其临床特点的相关性研究

目的 探讨我国汉族人群中mTOR基因的单核苷酸(SNP)位点(rs2295080)多态性与T2DM及其相关临床指标变化的相关性. 方法 采用病例对照研究,分别选取T2DM患者(T2DM组)213例和同期体检健康者(NC组)248名.采用聚合酶链反应-限制性片断长度多态性分析法(PCR-RFLP)测定mTOR基因SNP位点(rs2295080)多态性分布,并进行统计学分析. 结果 T2DM组SNP位点(rs2295080)基因型频率与NC组比较,差异有统计学意义(P=0.046),等位基因T频率高于NC组(OR=1.493,95％CI:1.077～2.069,P=0.016).T2DM组该位点多态性与FPG、HbA1 c、HDL-C、LDL-C及TC无相关性(P＞0.05),与TG相关(P＜0.05). 结论 mTOR基因SNP位点多态性与T2DM发病相关,且在T2DM患者中,SNP位点rs2295080多态性与TG水平相关.     

TSPAN8基因多态性与广西扶绥县肝癌家系遗传易感性关系研究

目的探讨广西扶绥县肝癌高发家系TSPAN8基因单核苷酸多态性(SNP)与肝癌遗传易感性的关系。方法收集广西扶绥县肝癌高发区20个肝癌高发家系(肝癌患者20例及直系亲属59例)及10个正常对照家系(共40例)作为研究对象,运用飞行时间质谱分析技术(MALDI-TOF)检测TSPAN8基因rs2270587位点基因型,分析该基因位点多态性与肝癌家系遗传易感性的关系。结果 (1)TSPAN8基因rs2270587位点存在C、T两种等位基因型及CC、CT和TT三种基因型。(2)正常家系组及肝癌家系非患者组CT基因型个体罹患HCC的风险分别是CC基因型个体的0.34倍(95%CI=0.07~1.59,P0.05)和0.42倍(95%CI=0.11~1.66,P0.05);正常家系组中T等位基因个体罹患HCC的风险是C等位基因个体的0.29倍(95%CI=0.09~0.92,P=0.028),肝癌家系非患者组中T等位基因个体罹患HCC的风险是C等位基因个体的0.46倍(95%CI=0.15~1.42,P0.05)。结论 TSPAN8基因rs2270587位点多态性与广西肝癌遗传易感性有相关性,T等位基因型可能是广西扶绥县HCC发生的保护因素。     

Cytochrome 1A1 and 1B1 gene diversity in the Zanzibar islands

Amodiaquine (AQ) is a 4‐aminoquinoline widely used in the treatment of malaria as part of the artemisinin combination therapy (ACT). AQ is metabolised towards its main metabolite desethylamodiaquine mainly by cytochrome P450 2C8 (CYP2C8). CYP1A1 and CYP1B1 play a minor role in the metabolism but they seem to be significantly involved in the formation of the short‐lived quinine‐imine. To complete the genetic variation picture of the main genes involved in AQ metabolism in the Zanzibar population, previously characterised for CYP2C8, we analysed in this study CYP1A1 and CYP1B1 main genetic polymorphisms. The results obtained show a low frequency of the CYP1A1*2B/C allele (2.4%) and a high frequency of CYP1B1*6 (approximately 42%) followed by CYP1B1*2 (approximately 27%) in Zanzibar islands. Genotype data for CYP1A1 and CYP1B1 show a low incidence of fast metabolisers, revealing a relatively safe genetic background in Zanzibar’s population regarding the appearance of adverse effects.     

CYP1A1 , GSTM1 , GSTT1 and NQO1 polymorphisms and colorectal adenomas in Japanese men

AIM: To investigate the role of functional genetic poly-morphisms of metabolic enzymes of tobacco carcinogens in the development of colorectal adenomas. METHODS: The study subjects were 455 patients with colorectal adenomas and 1052 controls with no polyps who underwent total colonoscopy in a preretirement health examination at two Self Defense Forces hospitals. The genetic polymorphisms studied wereCYP1A1*2A (rs 4646903), CYP1A1*2C (rs 1048943), GSTM1 (null or non-null genotype), GSTT1 (null or non-null genotype) and NQO1 C609T (rs 1800566). Genotypes were determined by the polymerase chain reaction (PCR)-restriction fragment length polymorphism or PCR method using genomic DNA extracted from the buffy coat. Cigarette smoking and other life-style factors were ascertained by a self-administered questionnaire. The associations of the polymorphisms with colorectal adenomas were examined by means of OR and 95%CI, which were derived from logistic regression analysis. Statistical adjustment was made for smoking, alcohol use, body mass index and other factors. The gene-gene interaction and effect modification of smoking were evaluated by the likelihood ratio test. RESULTS: None of the five polymorphisms showed a significant association with colorectal adenomas, nor was the combination of GSTM1 and GSTT1 . A borderline significant interaction was observed for the combination of CYP1A1*2C and NQO1 (P = 0.051). The OR associated with CYP1A1*2C was significantly lower than unity among individuals with the NQO1 609CC genotype. The adjusted OR for the combination of the CYP1A1*2C allele and NQO1 609CC genotype was 0.61 (95%CI: 0.42-0.91). Although the interaction was not statistically significant (P = 0.24), the OR for individuals carrying the CYP1A1*2C allele and GSTT1 null genotype decreased significantly compared with those who had neither CYP1A1*2C allele nor GSTT1 null genotype (adjusted OR: 0.69, 95%CI: 0.49-0.97). Smoking did not modify the associations of the individual polymorphisms with colorectal adenomas. There w     

Inhibition of procarcinogen-bioactivating human CYP1A1, CYP1A2 and CYP1B1 enzymes by melatonin

Abstract:  Administration of melatonin to rodents decreases the incidence of tumorigenesis initiated by benzo[ a ]pyrene or 7,12-dimethylbenz[ a ]anthracene, which requires bioactivation by cytochrome P450 enzymes, such as CYP1A1, CYP1A2 and CYP1B1, to produce carcinogenic metabolites. The present study tested the hypothesis that melatonin is a modulator of human CYP1 catalytic activity and gene expression. As a comparison, we also investigated the effect of melatonin on the catalytic activity of CYP2A6, which is also a procarcinogen-bioactivating enzyme. Melatonin (3–300 μ m ) decreased 7-ethoxyresorufin O -dealkylation catalyzed by human hepatic microsomes and recombinant CYP1A1, CYP1A2 and CYP1B1, whereas it did not affect coumarin 7-hydroxylation catalyzed by hepatic microsomes or recombinant CYP2A6. Melatonin inhibited CYP1 enzymes by mixed inhibition, with apparent K _i values (mean ± S.E.M.) of 59 ± 1 (CYP1A1), 12 ± 1 (CYP1A2), 14 ± 2 (CYP1B1) and 46 ± 8 μ m (hepatic microsomes). Additional experiments indicated that melatonin decreased benzo[ a ]pyrene hydroxylation catalyzed by hepatic microsomes and CYP1A2 but not by CYP1A1 or CYP1B1. Treatment of MCF-10A human mammary epithelial cells with melatonin (up to 300 μ m ) did not affect basal or benzo[ a ]pyrene-inducible CYP1A1 or CYP1B1 gene expression. Consistent with this finding, melatonin did not influence reporter activity in aryl hydrocarbon receptor-dependent pGudluc6.1-transfected MCF-10A cells treated with or without benzo[ a ]pyrene, as assessed in an in vitro cell-based luciferase reporter gene assay. Overall, melatonin is an in vitro inhibitor of human CYP1 catalytic activity, and it may be useful to develop potent analogues of melatonin as potential cancer chemopreventive agents that block CYP1-mediated chemical carcinogenesis.     

Pandemic H1N1 influenza

The 2009 H1N1 influenza A virus that has targeted not only those with chronic medical illness, the very young and old, but also a large segment of the patient population that has previously been afforded relative protection - those who are young, generally healthy, and immune naive. The illness is mild in most, but results in hospitalization and severe ARDS in an important minority. Among those who become critically ill, 20-40% will die, predominantly of severe hypoxic respiratory failure. However, and potentially in part due to the young age of those affected, intensive care with aggressive oxygenation support will allow most people to recover. The volume of patients infected and with critical illness placed substantial strain on the capacity of the health care system and critical care most specifically. Despite this, the 2009 pandemic has engaged our specialty and highlighted its importance like no other. Thus far, the national and global critical care response has been brisk, collaborative and helpful - not only for this pandemic, but for subsequent challenges in years ahead.     

1-Naphthyl isocyanate and 1-naphthylamine as metabolites of 1-naphthylisothiocyanate

Abstract: The importance of the bioactivation of 1-naphthylisothiocyanate was studied. Forty minutes after 1-naphthylisothiocyanate administration to rats, bile was collected over a 2.5-h period; the liver was then excised and homogenized. 1-naphthylisothiocyanate and its metabolites in bile and liver of rats were identified and quantified using coupled gas chromatography-mass spectrometry. Three main compounds were found in all 1-naphthylisothiocyanate-treated animals. They were identified as 1-naphthyl isocyanate, 1-naphthylamine and the parent compound, 1-naphthylisothiocyanate. When rats were given cycloheximide, which attenuates 1-naphthylisothiocyanate toxicity, 30 min before 1-naphthylisothiocyanate (300 mg/kg), 1-naphthyl isocyanate concentration was significantly lower than in rats receiving only 1-naphthylisothiocyanate. The appearance of 1-naphthylamine was also inhibited by cycloheximide, although not to the same extent as 1-naphthyl isocyanate. On the other hand, phenobarbital, which potentiates 1-naphthylisothiocyanate hepatotoxicity, enhanced 1-naphthyl isocyanate and 1-naphthylamine formation. It is suggested that 1-naphthyl isocyanate, 1-naphthylamine and the highly reactive sulfur released from 1-naphthylisothiocyanate might be involved in the hepatotoxic effect of 1-naphthylisothiocyanate.     

Sulfotransferase 1A1 (SULT1A1) polymorphism and susceptibility to primary brain tumors

Purpose Sulfotransferase 1A1 is a member of sulfotransferase family that plays an important role in the biotransformation of numerous carcinogenic and mutagenic compounds through sulfation. The present study has investigated the association between SULT1A1 polymorphism and primary brain tumor incidence. Methods SULT1A1 genotypes were successfully detected using the PCR-RFLP assay in 60 primary brain tumor patients and 156 hospital-based healthy control individuals with no history of cancer or precancerous disorder. Results There was a significant difference in genotypes distribution (GG vs. GA + AA) between brain tumor patients (GG genotype frequency = 48.3%) and control population (GG genotype frequency = 65.4%; OR = 2.019, 95% CI = 1.103–3.695; P = 0.022). In order to determine the association between SULT1A1 polymorphism and specific types of brain tumors, the patients were classified according to the type of brain tumors they suffer from: glial and non-glial. Results of the statistical analyses of each group of patients in comparison with the control individuals showed a significant difference only between SULT1A1 polymorphism and non-glial brain tumors (OR = 2.615; 95% CI = 1.192–5.739; P = 0.014) but glial tumors (OR = 1.535; 95% CI = 0.688–3.425; P = 0.293). When non-glial tumors were classified as meningiomal and others (pituitary adenoma, craniopharyngioma, acoustic neuroma and hemangioblastoma), statistical analysis showed that this significance is only due to the meningiomal tumors (OR = 3.238; CI = 1.205–8.704; P = 0.015). We also estimated a reduced risk of brain tumor in non-smokers (OR = 1.700; CI = 0.800–3.615) in comparison to smokers (OR = 2.773; CI = 0.993–7.749), but this was not statistically significant. Conclusion Our findings have suggested that there was a significant association between brain tumor and SULT1A1*2 allele (A allele that is also known as His allele) and this allele is an important risk factor in the development of meningiomal brain tumors.     

The target of ezetimibe is Niemann-Pick C1-Like 1 (NPC1L1)

Ezetimibe is a potent inhibitor of cholesterol absorption that has been approved for the treatment of hypercholesterolemia, but its molecular target has been elusive. Using a genetic approach, we recently identified Niemann-Pick C1-Like 1 (NPC1L1) as a critical mediator of cholesterol absorption and an essential component of the ezetimibe-sensitive pathway. To determine whether NPC1L1 is the direct molecular target of ezetimibe, we have developed a binding assay and shown that labeled ezetimibe glucuronide binds specifically to a single site in brush border membranes and to human embryonic kidney 293 cells expressing NPC1L1. Moreover, the binding affinities of ezetimibe and several key analogs to recombinant NPC1L1 are virtually identical to those observed for native enterocyte membranes. KD values of ezetimibe glucuronide for mouse, rat, rhesus monkey, and human NPC1L1 are 12,000, 540, 40, and 220 nM, respectively. Last, ezetimibe no longer binds to membranes from NPC1L1 knockout mice. These results unequivocally establish NPC1L1 as the direct target of ezetimibe and should facilitate efforts to identify the molecular mechanism of cholesterol transport.