加强基因型分析发展个体化医学

疾病的诊断，从表型(phenotype)分析发展到表型和基因型( genotype)结合分析代表着医学的革命性进步。临床分子病理学，或称分子诊断，已成为当今迅猛兴起的病理亚学科之一。它从核酸水平（DNA和RNA）研究疾病发生和发展规律，揭示疾病时外源性基因在体内的存在和内源性基因的突变及表达异常，是传统形态病理学的有益补充和发展。

不同基因型丙型肝炎病毒感染临床研究

AIM To study the clinical peculiarities of patients infected with different genotypes of hepatitis C virus (HCV).METHODS Genotypes of HCV in 90 HCV-RNA-positive patients in Xuzhou area were examined. Clinical data of the patients were compared.RESULTS HCV Ⅱamounted to 78.9% (71/ 90), predominating over HCV Ⅲand HCV Ⅱ/ Ⅲwhich held 18.9% (17/ 90) and 2.2% (2/ 90) respectively in the area. ALT level and ALT positivity rate were higher in HCV Ⅱthan in HCV Ⅲ(P＜0.05) within a range of ＞200 U/ L. Anti-HCV OD value and anti-HCV positivity rate when its OD value was over 2, were lower in HCV Ⅱthan in HCV Ⅲ(P＜0.05). Most jaundice patients (87%) were infected with HCV Ⅱ. No significant difference was found in age, sex and transfusion experience between HCV Ⅱand HCV Ⅲpatients (P＞0.05).CONCLUSION Distribution of HCV genotypes in Xuzhou area is consistent with that in the whole China, reflecting its distribution in eastern coastal areas. The immunogenicity of HCV Ⅱis lower than that of HCV Ⅲ, but the damage of hepatic function is more serious in HCV Ⅱpatients than in HCV Ⅲpatients, which might be due to different pathogenic mechanisms. Infection with HCV Ⅱ/ Ⅲis related to repeated usage of blood products and repeated hemodialysis. HCV Ⅱand HCV Ⅲ, we believe, might play coordinated roles in pathogenesis.

Helicobacter pylori (H. pylori ) is a major causativebacterium of chronic gastritis, peptic ulcer and mucosaassociated lymphoid tissue lymphoma in humans, and associated with an increased risk of gastric cancer[1 -8]. An important virulant factor of H. pylori is the vacuolating cytotoxin ( VacA ) encoded by vacA that induces cytoplasmic vacuolation in target cells both in vitro and in vivo[9-11]. VacA is produced as a 140 kDa precursor which contains an N-terminal signal peptide and an approximately 33 kDa C-terminal outer membrance exporter. The precursor is cleaved at both N-terminal and C-terminal and secreted into the extracellular milieu as a 95 kDa mature protein. The mature protein futher undergoes specific cleavage to yield 37 kDa and 58 kDa subunits[12-14] Although vacA is present in all H. pylori strains, only about 50% to 60% of strains can induce vacuolation of epithelial cells as assessed by the HeLa cell assay. vacA shows considerable genetic variation in H. pylori isolated from all over the world and contains at least two variable regions. The s region exists as sl or s2 allelic types. Among type sl strains, subtypes sla and slb have been identified. The m region occurs as ml or m2 allelic types. Specific vacA genotype of H. pylori strains are associated with the production of the cytotoxin in vitro, epithelial damage in vivo, and clinical consequences[15-27]. The other virulant factor is the cytotoxin-associated protein (CagA) encoded by the cytotoxin-associated gene (cagA). The cagA gene is present in about 60% to 70% of strains and all of these strains express the cagA. The presence of cagA is also associated with the production of the cytotoxin in vitro, and clinical outcome[24-30]. The aim of this study was (i) to identify vacA genotypes and cagA status of H. pylori isolated from Chinese patients; (ii) to evaluation the relatioship beween vacA genotypes, cagA status and related gastroenterological disorders.

Objective To investigate the association between HBV genotypes and characteristics of rtA181 mutation. Methods Total of 85 chronic hepatitis B (CHB) patients who appeared rtA181 mutation after nucleos(t)ide analogs (NAs) therapy were enrolled in this study. Levels of serum ALT, AST, HBV DNA and HBsAg titers were monitored during therapy. HBV reverse transcriptase genes were amplified and sequenced to identify genotypes and resistance mutations. Virions and HBsAg in HepG2 cell with rtA181 mutation were also compared between genotypes B and C. Results The majority of sera contained HBV genotypes B (15.7%) and C (84.3%). There were no significant difference of rtA181 mutant patterns between genotypes (P> 0.05). After emergence of rtA181 mutation, serum ALT, AST, HBV DNA levels and HBsAg titers were decreased than that at baseline (P<0.05), while these characteristics were not different between genotypes B and C (P>0.05). In cellular experiment, there were no significant differences between genotypes B and C not only in HBV virions but also in HBsAg titres (P>0.05). Conclusions No differences of clinical characteristics and cellular results were found in rtA181 mutation of HBV genotypes B and C.

Objective To investigate the occurrence of basal core promoter (BCP) and pre-C mutations in patients with hepatitis B virus (HBV) infection in Gansu Province, China, and to analyze the correlation of HBV mutation and HBV genotype with primary hepatocellular carcinoma (HCC). Methods PCR-RFLP was applied to detect HBV subgenotypes, and the presence of the pre-C and BCP mutations in 62 patients with HCC, 70 patients with hepatitis B induced liver cirrhosis (LC) and 90 patients with chronic hepatitis B (CHB). Results In HCC patients, genotype C was the major genotype (70.97%). The pre-C mutation was found in 59.68%, 31.43% and 16.67% patients with HCC, LC and CHB, respectively. The frequency of BCP mutations was signiifcantly different between patients with HCC, LC and CHB (74.19%, 51.43% and 37.78%, respectively;χ2=30.727, 19.540, respectively,P < 0.01). Patients in HCC group had a higher incidence of pre-C as well as BCP mutations compared to the other groups. The prevalence of pre-C and BCP mutations was signiifcantly higher in patients with genotype C1 (44.32% and 69.32%, respectively) compared to patients with other subgenotypes (P < 0.05). Conclusions The incidence of pre-C and BCP mutations increases with disease progression. Pre-C and BCP mutations frequently occur in patients with genotype C1. HBV genotype C, pre-C mutations and BCP mutations are closely related to the occurrence of HCC.

A previous study of European Caucasian patients with sporadic amyotrophic lateral sclerosis demonstrated that a polymorphism in the microtubule-associated protein Tau (MAPT) gene was significantly associated with sporadic amyotrophic lateral sclerosis pathogenesis. Here, we tested this association in 107 sporadic amyotrophic lateral sclerosis patients and 100 healthy controls from the Chinese Han population. We screened the mutation-susceptible regions of MAPT-the 3′and 5′untranslated regions as wel as introns 9, 10, 11, and 12-by direct sequencing, and identified 33 genetic variations. Two of these, 105788 A>G in intron 9 and 123972 T>A in intron 11, were not present in the control group. The age of onset in patients with the 105788 A>G and/or the 123972 T>A variant was younger than that in patients without either genetic variation. Moreover, the pa-tients with a genetic variation were more prone to bulbar palsy and breathing difficulties than those with the wild-type genotype. This led to a shorter survival period in patients with a MAPT genetic variant. Our study suggests that the MAPT gene is a potential risk gene for sporadic amyotrophic lateral sclerosis in the Chinese Han population.

Objective　To confirm the genetic relation between Giardia lamblia (G. lamblia) isolates from different geographic regions of China and other countries.Methods　Genomic DNA were extracted from the trophozoites or cysts of Giardia lamblia. The triose phosphate isomerase (tim) gene was amplified using polymerase chain reaction (PCR) technique. PCR products were digested with endonuclease and sequenced. The data of sequencing were analyzed with the DNAstar software and compared with that of the isolates acquired from GenBank.Results　Of nine isolates of Giardia lamblia from China (C1, C2, CH2 and CH3), Cambodia (CAM), Australia (A1 and A2) and America (BP and CDC), respectively, 3 (A1, A2 and CAM) fit into Group 1 (WB), 2 (CH2 and CH3)) into Group 2, and 4 (C1, C2, BP and CDC) into Group 3 (GS). The results confirmed the genetic relatedness of G. lamblia isolates from all over the world.Conclusion　Genotyping isolates of G. Lamblia provides important information for establishing the phylogenetic relationship or for the epidemiological evaluation of the spreading of this organism.

关注并开展血液病表观遗传学研究

生物个体的基因型(genotype)决定其表现型(Phenotype),表观遗传学是研究基因型到表现型之间转换的过程和机制.现在可将真核细胞内所含的信息分为两种:有形的遗传学信息和无形的表观遗传学信息.

TNFSF4基因多态性与系统性红斑狼疮的相关性研究

目的 探讨湖北汉族人群OX40配体蛋白基因rs844648位点和rs3850641位点基因多态性与SLE的相关性.方法 SLE患者82例和正常人对照组100例,采用PCR及限制性片段长度多态性方法(PCR-RFLP)检测TNFSF4基因rs844648和rs3850641位点多态性分布.结果 ①SLE组rs844648位点AA、AG和GG基因型频率分别为20.7％、62.2％、17.1％,正常人对照组为14.0％、55.0％、31.0％.SLE组rs844648多态性位点A等位基因携带者显著高于正常人对照组[73.2％比69.0％％,x2=4.69,P＜0.05,OR值=2.182( 1.068～ 4.458)],SLE组与正常人对照组间差异有统计学意义；②SNP位点rs3850641的正常人对照组AA、AG和GG基因型频率分别是76.0％、21.0％和3.0％,而SLE组分别为62.2％、31.7％和6.1％,SLE组rs3850641位点G等位基因携带者显著高于正常人对照组[37.8％比24.0％,x2=4.07,P＜0.05,OR值=1.925 (1.015 ～ 3.651)],SLE组与正常人对照组间差异有统计学意义.结论 TNFSF4基因rs844648和rs3850641位点存在单核苷酸多态性变异,该多态性与湖北地区汉族人群SLE的发病有相关性.

CYP2D6*10B基因型对中国人普罗帕酮对映体药动学的影响

AIM: To study the relationship between genotype of CYP2D6*10B and pharmacokinetics of propafenone enantiomers. METHODS: Genotype of 17 healthy Chinese HAN subjects was determined by an allele specific amplification method. The blood samples (0-15 h) of the subjects were taken after oral administration of a single dose (400 mg) of propafenone hydrochloride. Concentrations of propafenone enantiomers in plasma were mea sured by a reverse-phase HPLC with precolumn derivatization. RESULTS: Seventeen subjects characterized for CYP2D6* 1 0B genotype included (* 1/* 1) (n = 4), (* 1/* 10) (n = 5) and (* 10/* 10) (n = 8). The metabolic ratios (lg MR) of the three genotypes were -2.68+0.23, -2.2+0.7, and -1.1 +0.5, respectively. The AUC of the three groups that of *1/*10 group or *1/*1 group, and the CL of both enantiomers in *10/*10 is only half of that of *1/*10 group or * 1/* 1 group (P＜0.05). CONCLUSION: CYP2D6* 10B alleles induce the declined activity of CYP2D6 and impair the metabolism of propafenone.