首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到18条相似文献,搜索用时 171 毫秒
1.
目的研究自然抗性相关巨噬细胞蛋白1(NRAMPl)基因3′端非编码区(3′UTR)和维生素D受体(VDR)基因FokI、TaqI位点多态性与新疆哈萨克族人群结核病易感性的关联;分析NRAMPl基因和VDR基因交互作用对新疆哈萨克族人群结核病易感性的影响。方法采用病例对照研究方法,选取新疆哈萨克族活动性肺结核病患者213例,同地区同种族健康者211例。用聚合酶链反应 限制性片断长度多态性(PCR RFLP)分析方法对NRAMP1基因3′UTR、VDR基因FokI和TaqI多态性位点基因分型,采用χ2检验分析3个位点多态性与新疆哈萨克族结核病易感性的关系,相乘模型分析NRAMPl基因和VDR基因交互作用。结果1. NRAMPl基因3′UTR位点在病例组和对照组中TGTG/TGTG、TGTG/del和TGTGdel/del基因型频率分别为64.8%、29.6%、5.6%和79.1%、19.5%、1.4%。TGTGdel等位基因组间分布差异有统计学意义(χ2=13.737,P<0.01)。2. VDR基因FokI位点在病例组和在对照组中FF、Ff和ff基因型频率分别为33.8%、45.1%、21.1%和47.9%、41.7%、10.4%。f等位基因频率组间分布差异有统计学意义(χ2=13.868,P<0.01);TaqI位点TT、Tt和tt基因型组间分布差异无统计学意义;等位基因T和t组间分布差异无统计学意义(χ2=1.267,P>0.05);D'=0.477,r2=0.01,两位点不存在连锁不平衡。3. NRAMP1基因和VDR基因存在正交互作用,ORint=1.62。结论1. TGTG/del和TGTGdel/del基因型、TGTG缺失等位基因可能是新疆哈萨克族人群结核病易感基因。2. VDR基因中FokI多态性与新疆哈萨克族结核病易感性有关联,等位基因f可能是新疆哈萨克族结核病易感基因。3. NRAMP1和VDR基因间交互作用可能增加新疆哈萨克族人群结核病的发病风险。  相似文献   

2.
目的探讨生物代谢酶细胞色素P4501A1、谷胱甘肽转硫酶M1、T1基因多态性与儿童急性淋巴细胞白血病(ALL)的相关性。方法采用病例对照研究方法,应用聚合酶链反应-限制性片段长度多态性(PCR-RFLP)技术对89例儿童ALL患儿以及90名健康对照者的CYP1A1 Msp Ⅰ多态(T264C)、GSTMI和GSTT1等基因的多态分布进行分析。结果儿童ALL组的CYP1A1基因Msp Ⅰ多态纯合子突变型(C型)的频率与对照组差异有统计学意义(P0.05),携带纯合子突变型的儿童患ALL的危险度比杂合子突变型(B型)与野生型(A型)儿童的高(OR=1.997,95% CI:1.024~3.896)。GSTM1缺失型分布频率与对照组相比差异有统计学意义(P0.05,OR=2.709,95%CI:1.427~5.146),GSTT1缺失型分布频率与对照组相比差异无统计学意义(P0.05)。同时携带CYPlAl C型、GSTM1、GSTT1缺失型的联合基因型儿童患ALL的风险增加(OR=2.235,95% CI:1.111~4.497)。结论 CYP1A1基因Msp Ⅰ多态纯合子突变型(C型)、GSTM1缺失型与儿童ALL的易感性可能相关,GSTT1缺失型与儿童ALL易感性可能不相关;同时携带CYP1A1 C型与GSTM1、GSTT1缺失基因型可能是儿童ALL发病的易感因素之一。  相似文献   

3.
GSTT1及GSTM1与急性髓系白血病疗效及预后的研究   总被引:3,自引:0,他引:3  
目的探讨谷胱甘肽硫转移酶(GSTs)家族中GSTT1和GSTM1基因多态性与急性髓系白血病(AML)疗效,药物不良反应与预后的关系。方法AML患者180例,用多重PCR方法检测GSTT1和GSTM1基因型,比较不同基因型患者的诱导治疗完全缓解(CR)率,药物不良反应发生率,总体生存期,无复发生存期和复发率。结果(1)GSTT1和GSTM1基因双非缺失型(double-present型)患者一疗程CR率高于GSTT1,GSTM1任一基因缺失型(null型),二者差异有统计学意义(P=0.013),GSTT1/GSTM1的null基因型患者发生不CR的危险度是double-present型患者的8.736倍(95%CI1.146~66.574)。GSTT1present型一疗程CR率高于GSTT1null型,二者比较亦有统计学意义(P=0.021,OR=2.572,95%CI1.136~5.826);(2)GSTT1和GSTM1基因型分布与诱导治疗后中性粒细胞<0.5×109/L及PLT<20×109/L持续时间差异无统计学意义,GSTM1null型患者发生AST异常的危险度是GSTM1present型的2.593倍(P=0.016,95%CI1.176~5.717);(3)double-present型总体和无复发生存期较GSTT1/GSTM1的null型患者长(平均总体生存期为68.4、38.5个月,P=0.028;平均无复发生存期为73.5、34.9个月,P=0.014),GSTT1null型患者无复发生存期短于GSTT1present型患者(平均无复发生存期为26.7、64.3个月,P=0.038),但二者总体生存期无统计学意义(P=0.653)。double-present型患者复发率显著低于GSTT1/GSTM1的null型患者(13.3%、35.6%,P=0.019)。结论GSTT1,GSTM1基因型与AML患者治疗CR率、复发率、化疗的不良反应及预后均有显著相关性,GSTT1和GSTM1基因型有助于指导AML患者个体化治疗方案的制定。  相似文献   

4.
目的探讨中国汉族人群谷胱甘肽硫转移酶(glutathione S-transferases,GST)M1及T1基因(GSTM1/GSTT1)多态性与先天性心脏病(先心病)发病风险的关系。方法采用病例-对照研究(病例组365例,对照组372例),运用多重聚合酶链反应检测先心病患者及健康对照GSTM1/GSTT1基因型;并利用多因素非条件logistic回归模型,进行先心病发病风险影响因素关联强度及交互作用分析。结果 GSTM1/GSTT1基因多态性及研究对象母亲围孕期吸烟、饮酒、化学物质接触、孕前体质量指数、教育程度、定期产检以及怀孕知情时间在病例组和对照组之间分布存在明显差异(P<0.05)。GSTM1/GSTT1基因缺失与先心病发病风险显著正相关(OR=1.56,P=0.049;OR=1.73,P=0.036)。经logistic回归分析,GSTM1(-)/GSTT1(-)基因型和研究对象母亲围孕期吸烟、饮酒、化学物质接触以及孕前高体质量指数是先心病发病的高危因素,研究对象母亲围孕期定期产检以及摄入充足的叶酸是先心病的保护因素。研究对象母亲围孕期吸烟与GSTM1(-)/GSTT1(-)基因型之间具有正相加交互作用,与母亲围孕期不吸烟且GSTM1/T1基因未缺失的研究对象相比,其母亲围孕期吸烟且携带GSTM1(-)和(或)GSTT1(-)基因型的先心病发病风险显著上升(OR=9.01,3.87,3.01;95%CI:1.73~39.69,1.21~19.57,1.13~9.69)。结论 GSTM1/GSTT1基因缺失是先心病发病风险的独立危险因素;GSTM1(-)/GSTT1(-)基因型与孕母围孕期吸烟在先心病的发生中具有协同作用。  相似文献   

5.
Zhu Y  Deng C  Zhang Y  Zhou X  He X 《中华内科杂志》2002,41(8):538-540
目的 探讨谷胱甘肽S 转移酶 (GST)M1、T1基因多态与散发性大肠腺癌 (SCRAC)遗传易感性的关联。方法 应用多重聚合酶链反应 (PCR)技术 ,对经病理组织学确诊的 10 4例SCRAC患者及同期在本院体检的无血缘关系的 10 1例健康人 ,检测其GSTM1和GSTT1基因多态性。结果  (1)在健康人和SCRAC患者 ,GSTM1、GSTT1空白基因型的频率差异均无显著性 (前者 4 6 5 % :5 6 7% ,χ2 =2 13,P >0 0 5 ;后者 4 7 5 % :6 0 6 % ,χ2 =3 5 2 ,P >0 0 5 )。 (2 )GSTM1空白基因型频率在近端与远端SCRAC患者间、在老年与非老年SCRAC间的频率差异均无显著性 ;而GSTT1空白基因型的频率差异有显著性 (前者 4 4 4 % :6 6 2 % ,χ2 =3 97,P <0 0 5 ;后者 70 9% :4 9 0 % ,χ2 =5 2 1,P <0 0 5 )。 (3)GSTM1、GSTT1均为空白基因联合型的个体患SCRAC的危险性升高 4 33倍 (9 6 % :2 6 9% ,χ2 =7 89,ν =3,P <0 0 5 )。结论 单独的GSTM1或GSTT1空白基因型与SCRAC遗传易感性无关 ,但GSTT1空白基因型与远端SCRAC遗传易感性有关 ,且多见于老年患者。GSTM1、GSTT1均为空白基因的联合基因型是SCRAC的易感基因型。  相似文献   

6.
目的探讨谷胱甘肽硫转移酶M1和T1(GSTM1、GSTT1)基因多态性与燃煤污染型砷中毒发病风险的关系。方法采用多重等位基因特异聚合酶链反应技术检测贵州省130名燃煤型砷中毒患者及140名健康个体的GSTM1和GSTT1基因多态性,并分析不同基因型与砷中毒发病的关系。结果砷中毒病例组和对照组GSTT1纯合缺失基因型(GSTT1^(-/-))的频率分别为58.5%和45.0%,组间比较差异有统计学意义(Х^2=6.246,P〈0.05);携带GSTT1^(-/-)基因型个体发生砷中毒的风险是携带GSTT1非纯合缺失基因型(GSTT1^(+/+)or(-/-))个体的2.18倍[比值比(OR)adj=2.18,95%可信区间(CI):1.183~4.018]。砷中毒病例组和对照组间GSTM1纯合缺失基因型(GSTM1^(-/-))频率的差异无统计学意义(P〉0.05)。基因型联合分析显示:携带GSTM1^(-/-)和GSTT1^(-/-)联合基因型的个体,其砷中毒的发病风险显著增加(ORadj=2.931,95%CI:1.024~8.387)。结论GSTT1^(-/-)基因型可能是燃煤型砷中毒发生的重要危险内因之一。  相似文献   

7.
目的探讨哈萨克族人群内皮型一氧化氮合酶(eNOS)基因多态性与原发性高血压关联性.方法应用聚合酶链反应、限制性内切酶方法检测了新疆巴里坤县203例哈萨克族高血压病患者和190例正常人群eNOS基因G894T多态性.结果哈萨克族正常人群及高血压患者的eNOS基因G894T多态GG、GT、TT基因型频率分布分别为0.74,0.24,0.02和0.81,0.18,0.01,G和T等位基因分布频率分别为0.86,0.14和0.90,0.10,符合Hardy-Weinberg平衡.群体相关分析结果表明eNOS基因的G及T等位基因分布在高血压病组(EH)及正常血压组(NT)差异无显著性(χ2=3.580,P=0.058);基因型频率之间差异无显著性(χ2=4.037,P=0.133).然而男性EH组G等位基因频率(0.90)高于NT组(0.86);T等位基因频率(0.06)低于NT组(0.14).结论 eNOS基因G894T多态性可能与新疆巴里坤哈萨克族男性高血压有关.  相似文献   

8.
目的探讨哈萨克族人群内皮型一氧化氮合酶(eNOS)基因多态性与原发性高血压关联性.方法应用聚合酶链反应、限制性内切酶方法检测了新疆巴里坤县203例哈萨克族高血压病患者和190例正常人群eNOS基因G894T多态性.结果哈萨克族正常人群及高血压患者的eNOS基因G894T多态GG、GT、TT基因型频率分布分别为0.74,0.24,0.02和0.81,0.18,0.01,G和T等位基因分布频率分别为0.86,0.14和0.90,0.10,符合Hardy-Weinberg平衡.群体相关分析结果表明eNOS基因的G及T等位基因分布在高血压病组(EH)及正常血压组(NT)差异无显著性(x2=3.580,P=0.058);基因型频率之间差异无显著性(x2=4.073,P=0.133).然而男性EH组G等位基因频率(0.90)高于NT组(0.86);T等位基因频率(0.06)低于NT组(0.14).结论eNOS基因G894T多态性可能与新疆巴里坤哈萨克族男性高血压有关.  相似文献   

9.
目的:研究血管紧张素Ⅱ 1型受体(AT1R)基因573T>C和1166A>C多态性与新疆哈萨克族原发性高血压(EH)的关系.方法:采用病例-对照研究随机选取新疆哈萨克族牧民EH患者(EH组)194例,正常血压者(对照组)115例,采用聚合酶链反应和限制性片段长度多态性技术检测AT1R基因573T>C和1166A>C多态性,用最大似然法估计两位点单体型频率.结果:AT1R基因573T>C多态性在EH组中T、C等位基因频率分别为0.799,0.201,对照组中T、C等位基因频率分别为0.713和0.287,EH组T等位基因频率高于对照组(P<0.05).1166A>C位点仅在EH组检测到1例CC基因型,A、C 2种等位基因和基因型频率在2组间分布差异无统计学意义(均P>0.05).573T>C和1166A>C间未检测到连锁不平衡.T573-A1166组成的单体型频率最高,占70.4%,其次是C573-A1166,为17.1%.2组间单体型分布差异无统计学意义(P>0.05).不同单体型对EH的影响差异无统计学意义(均P>0.05).结论:AT1R基因573T>C的T等位基因和TT及TC基因型是新疆哈萨克族EH可能的易感因素,而573T>C和1166A>C组成的单体型可能与新疆哈萨克族EH无关.  相似文献   

10.
WNK4基因多态性与新疆哈萨克族原发性高血压的关系   总被引:1,自引:0,他引:1  
目的 探讨新疆哈萨克族WNK 4(with no K=lysine kinase)基因内含子10(intron10)多态性与原发性高血压间的关系,了解该基因多态性在哈萨克族人群中的分布情况.方法 采用直接测序法测定WNK 4基因intron10序列,确定单核苷酸多态性位点及类型,应用多聚酶链反应、限制性片段长度多态性技术(PCR-RFLP)对该位点进行基因分型,其中原发性高血压患者191例(高血压组)、健康对照组173例.结果 在WNK 4基因intron10发现一多态性位点(17号染色体上碱基1156666,G→A);PCR-RFLP分型,GG、GA、AA各基因型在哈萨克族高血压组和健康对照组的频率分别为88.0%、11.0%、1.0%和91.9%、8.1%、0%,差异无统计学意义(均为P>0.05);A等位基因频率分别为6.5%和4.0%,差异无统计学意义(P>0.05).结论 WNK 4基因intronl0多态性可能不是新疆哈萨克族原发性高血压的遗传易感指标.  相似文献   

11.
~~Glutathione-S-transferase M1 polymorphisms on the susceptibility to esophageal cancer among three Chinese minorities:Kazakh,Tajik and Uygur1 Parkin DM, Bray F, Ferlay J, Pisani P. Estimating the world cancer burden: Globocan 2000. Int J Cancer 2001; 94:…  相似文献   

12.
OBJECTIVE: The aim of this study was to determine whether null genotypes for glutathione transferase mu-1 (GSTM1) and theta-1 (GSTT1) influence the risk of development of advanced alcoholic liver disease. MATERIAL AND METHODS: GSTM1 and GSTT1 genotypes were identified on DNA through multiple analysis with polymerase chain reaction in 153 subjects diagnosed with advanced alcoholic liver disease and in 241 healthy controls. RESULTS: The frequency of the GSTM1 null genotype was not different between patients and controls (36.6% versus 41.1%, non-significant). The GSTT1 null genotype was more frequently found in patients than in controls (32% versus 22%, odds ratio 1.67, 95% CI 1.03-2.71, p =0.027). Moreover, patients were more likely to be simultaneous carriers of both GSTM1 and GSTT1 null genotypes (odds ratio 4.30, 95% CI 1.89-9.97, p =0.0003). CONCLUSIONS: The GSTT1 null genotype is more frequent among patients with advanced alcoholic liver disease than in controls. The coincidence of this genotype with the GSTM1 null genotype is four times more likely in patients. We suggest that polymorphisms affecting the activity of the glutathione S-transferase isoforms M1 and T1 may be associated with the risk of developing chronic severe ethanol liver damage.  相似文献   

13.
Wang D  Wang B  Zhai JX  Liu DW  Sun GG 《Neoplasma》2011,58(4):352-359
There were some studies on the associations between Glutathione S-transferase M1 (GSTM1) and Glutathione S-transferase T1 (GSTT1) polymorphisms and cervical cancer (CC) risk, but the results were inconsistent. Thus, a meta-analysis was performed. The electronic databases PubMed, Science Direct, CBM, and CNKI were searched for possible studies. Finally, 16 studies (1,627 cases and 2,161 controls) were included. For the GSTM1 and GSTT1 polymorphisms, the unadjusted odds ratios (OR) and 95% confidence intervals (95% CI) from each study were used to estimate summary OR. Subgroup analyses by ethnicity and histological type of CC were also performed. For the GSTM1 polymorphism, the null genotype of GSTM1 was associated with an increased CC risk in total population (OR=1.32, 95% CI=1.06-1.66). Similar association was found in Asians (OR=1.47, 95% CI=1.11-1.94), but not in Caucasians (OR=0.96, 95% CI=0.73-1.27). For the GSTT1 polymorphism, the null genotype of GSTT1 was not statistically significantly associated with CC risk in total population (OR=1.36, 95% CI=0.97-1.90). This result was also found in Asians (OR=1.27, 95% CI=0.87-1.85) and Caucasians (OR=1.09, 95% CI= 0.66-1.79), but not in Latinos (OR=4.58, 95% CI= 2.04-10.28). For the GSTM1/GSTT1 interaction analysis, the dual null genotypes of GSTM1/GSTT1 were significantly associated with increased CC risk in total population (OR=1.77, 95% CI= 1.14-2.75), and all the six studies were from Asia. For subgroup analyses by histological type of CC, the three aspects of the analyses above were all not significantly associated with CC risk in squamous cell carcinoma and adenocarcinoma, respectively. The null genotype of GSTM1 and the dual null genotypes of GSTM1/GSTT1 were risk factors in CC, and the null genotype of GSTT1 was not associated with CC risk.  相似文献   

14.
OBJECTIVES: Glutathione S-transferases (GST) modulate the effects of exposure to various cytotoxic and genotoxic agents, including those associated with increased risks of the myelodysplastic syndrome (MDS), acute myeloid leukaemia (AML) and aplastic anemia (AA). Both the GST mu 1 (GSTM1) and GST theta 1 (GSTT1) genes have a null variant allele in which the entire gene is absent. In this study, we tested whether null genotypes for the GSTM1 and GSTT1 genes altered the risks for MDS, AML and AA. METHODS: Genomic DNA from 49 MDS, 38 AML and 37 AA patients and 276 controls was analysed using the polymerase chain reaction (PCR). RESULTS: The frequencies of GSTM1 (73.6%) and GSTT1 (34.2%) null genotypes were significantly higher in AML patients than in the controls (36.9 and 18.1%, respectively). A higher frequency of the combined null genotype for both genes was also observed in patients with AML (26.3% compared with 5.0% in the controls). In contrast, no differences in the frequencies of the null genotypes were found among MDS patients, AA patients and the controls. CONCLUSION: Our observation of a 4.7-fold (95% CI: 2.1-11.0) and 2.3-fold (95% CI: 1.0-5.2) increased risk associated with the GSTM1 and GSTT1 null genotypes, respectively, and a 6.6-fold (95% CI: 2.4-7.9) increased risk associated with the combined null genotype presents preliminary evidence that the inherited absence of this carcinogen detoxification pathway may be an important determinant of AML.  相似文献   

15.
Glutathione S-transferases (GST) are a family of enzymes involved in phase-II detoxification of endogenous and xenobiotic compounds. Polymorphisms in GST genes have been associated with susceptibility to different diseases. In this study we determined the frequencies of polymorphisms in GSTM1, GSTT1, and GSTP1 in DNA of 138 children from Cameroon, presenting with uncomplicated malaria (N = 19), malaria with minor complications (N = 81), or severe malaria (N = 38). Analyses of GSTM1 and GSTT1 were performed using PCR-multiplex procedure, while GSTP1 was done by PCR-RFLP. Subjects presenting with malaria with complications were found more often of the GSTM1-null genotype (58-64%) as compared with those with uncomplicated malaria (32%), a difference that was statistically significant. We conclude that the GSTM1-null genotype is associated with malaria with complications.  相似文献   

16.
OBJECTIVES: Asthma is a complex multifactorial disease with an obvious genetic predisposition, immunological aberration, and involvement of noxious environmental factors. Polymorphisms of the glutathione-S-transferase (GST) genes are known risk factors for some environmentally-related diseases. In the present study, the hypothesis that polymorphisms in the GSTT1, GSTM1 and GSTP1 genes are associated with atopic and nonatopic asthma was examined. METHODOLOGY: The study population consisted of 103 unrelated healthy individuals and 101 patients with bronchial asthma (64 atopic, 37 nonatopic). Asthma was diagnosed according to the American Thoracic Society statement. Genotyping of polymorphisms in the GSTT1, GSTM1 and GSTP1 genes was performed using real time polymerase chain reaction with a Light Cycler instrument and hybridization probes in combination with the Light Cycler DNA master hybridization probes kit. RESULTS: Patients with atopic asthma (34.4%) had a higher prevalence of the GSTT1 null genotype than the nonatopic asthma patients (13.5%; OR = 3.83; 95% CI, 1.24-11.78). Asthma patients (63.4%) had a higher prevalence of the GSTM1 null genotype than the control group (40.8%; OR = 2.34; 95% CI, 1.31-4.20). Subjects with the GSTP1 homozygous Val/Val genotype had a 3.55-fold increased risk of having atopic asthma compared to nonatopic asthma (OR = 3.55; 95% CI, 1.10-12.56). CONCLUSIONS: These results suggest that the GSTT1 and GSTM1 null genotypes and the GSTP1 Val/Val polymorphism may play important roles in asthma pathogenesis. It is possible that intermediate electrophilic metabolites, arising in the first phase of detoxification, are not metabolized by GST enzymes in asthmatic patients and are not excreted. These intermediate metabolites may damage cells and generate oxidative stress, and so contribute to the pathogenesis of asthma.  相似文献   

17.
AIM: Glutathione S-transferase mu 1 (GSTM1) and theta 1 (GSTT1) genes are involved in the metabolism of a wide range of carcinogens, but deletions of the genes are commonly found in the population. The present study was undertaken to evaluate the association between GSTM1 and GSTT1 gene polymorphisms and hepatocellular carcinoma (HCC) risk. METHODS: The genetic polymorphisms were studied at an aflatoxin highly contaminated region in Guangxi, China. Pdymerase chain reaction (PCR) technique was used to detect the presence or absence of the GSTM1 and GSTT1 genes in blood samples. The case group was composed of 181 patients of HCC identified by the pathologists and the control group was composed of 360 adults without any tumor. RESULTS: The frequencies of GSTM1 and GSTT1 null genotypes in the control were 47.8% and 42.7%, while those in the HCC group were 64.6% and 59.7%, respectively. The differences between HCC group and control group were very significant (P<0.01). GSTM1 and GSTT1 combined null genotypes in HCC group and control group were 38.2% and 18.5% respectively, and the difference was significant (P<0.05). CONCLUSION: The GSTM1 and GSTT1 null genotypes are associated with an increased risk of HCC in a special geographic environment. Combination of the two null genotypes in an individual is substantially increased twice the risk of HCC.  相似文献   

18.
MIM:To test the hypothesis that,in the Southeastern Brazilian population,the GSTT1,GSTM1 and CYP2E1 polymorphisms and putative risk factors are associated with an increased risk for gastric cancer.METHODS:We conducted a study on 100 cases of gastric cancer(GC),100 cases of chronic gastritis(CG),and 150 controls(C).Deletion of the GSTT1 and GSTM1 genes was assessed by multiplex PCR.CYP2E1/PsА genotyping was performed using a PCR-RFLP assay.RESULTS:No relationship between GSTT1/GSTM1 deletion and the c1/c2 genotype of CYP2E1 was observed among the three groups.However,a significant difference between CG and C was observde,due to a greater number of GSTT1/GSTM1 positive genotypes in the CG group.The GSTT1 null genotype occurred more frequently in Negroid subjicts,and the GSTM1 null genotype was observed mainly in individuals with chronic gastritis infected with H pylori.CONCLUSION:Our findings indecate that there is no obvious relationship between the GSTT1,GSTM1 and CYP2E1 polymorphisms and gastric cancer.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号