Biomedical subjects

Min Gao

Publications and source records attributed to Min Gao.

At least 55 records · Page 3Linked to original sources

PubMed2005

Association of HLA-DQA1 and DQB1 alleles with alolpecia areata in Chinese Hans.

Accumulative evidences have shown that certain HLA loci are associated with alopecia areata (AA), but with existing differences in ethnic distribution. No report has ever been published about this in Chinese Hans. To investigate whether HLA-DQA1 and DQB1 alleles are associated with AA, and the correlation of the HLA profile with age of onset, severity, duration of current attack, recurrence and family history of AA in Chinese Hans. The polymerase chain reaction-sequence-specific primer (PCR-SSP) method was used to analyze the distribution of HLA-DQA1 and DQB1 alleles in 192 patients with AA and 273 healthy controls in Chinese Hans. The significant increased frequencies of HLA-DQA1*0104 (OR=3.38, P(c)<0.001), HLA-DQB1*0604 (OR=5.17, P(c)=0.006) and HLA-DQA1*0606 (OR=3.73, P(c)<0.001) were observed in patients compared with controls. The DQA1*0104-DQB1*0604, DQA1*0104-DQB1*0606, and DQA1*0302-DQB1*0606 were found as high-risk haplotypes in developing AA in this study. HLA-DQA1*0104 (OR=5.31, P(c)<0.001) and -DQB1*0604 (OR=5.56, P(c)=0.015) were more prevalent only in AA patients with long duration than controls. The frequencies of HLA-DQB1*0604 (OR=5.42, P(c)=0.009) and -DQB1*0606 (OR=4.11, P(c)<0.001) were obviously increased in patients less than 50% scalp hair loss. No locus was merely associated with early onset, severe involvement, recurrence and a positive family history of AA. This study demonstrated the positive association of HLA-DQA1 and DQB1 alleles and haplotypes with AA. There may be differences in genetic background in patients with different duration.

Adolescent↗

PubMed2005

Iptakalim, opener of K(ATP), reverses the enhanced expression of genes encoding K(ATP) subunits in spontaneously hypertensive rats.

ATP-sensitive potassium channels (K(ATP)) are thought to be targets for antihypertensive drugs that are potassium channel openers. In this study, the expression of genes encoding the K(ATP) subunits, SUR2, Kir6.1 and Kir6.2, was detected in tissues from Wistar-Kyoto rats (WKY), spontaneously hypertensive rats (SHR), and SHR undergoing long-term treatment with iptakalim, a novel antihypertensive drug that acts via K(ATP). The transcript levels for SUR2, Kir6.1 and Kir6.2 in the heart, aortic smooth muscle, and tail artery smooth muscle were determined by reverse transcription-polymerase chain reaction (RT-PCR). In general, Kir6.2 and SUR2 were more highly represented in all SHR tissues compared with those of WKY, and transcripts of Kir6.2 were significantly higher in tail artery smooth muscle from SHR. Following long-term treatment with iptakalim, mRNA levels of Kir6.2 and SUR2 were reduced significantly in all tissues compared with those of untreated SHR. Kir6.1 expression was not significantly different between SHR and WKY, and was unaffected by iptakalim treatment. These results indicate that the expression of the K(ATP) subunits genes, SUR2 and Kir6.2, are closely associated with hypertensive pathological states, and the effect of iptakalim on K(ATP) mRNA levels may explain, in part, the effects of iptakalim in reversing vascular and cardiac remodeling. Furthermore, changes in Kir6.2 mRNA levels suggest that Kir6.x, as well as SUR, is responsible for drug binding.

ATP-Binding Cassette Transporters↗

PubMed2005

Association of HLA class I alleles with aloplecia areata in Chinese Hans.

BACKGROUND: Some studies suggested that human HLA status may potentiate development of the AA phenotype and exists ethic differences. No report has been published about HLA class I alleles associated with AA in Chinese Hans. OBJECTIVE: To study the distribution of HLA class I alleles and haplotypes in Chinese Hans AA patients and the relation of HLA class I profile with age of onset, severity, duration of current attack, past history and family history. METHODS: The polymerase chain reaction-sequence-specific primer (PCR-SSP) method was used to analyze the distribution of HLA class I alleles in 192 patients with AA and 252 healthy controls in Chinese Hans. RESULTS: The frequencies of HLA-A*02, -A*03, -B*18, -B*27, -B*52 and -Cw*0704 were significantly higher in patients than in controls. The A*2-B*18, A*2-B*27, A*2-B*52, A*2-Cw*0704, B*18-Cw*0704, B*27-Cw*0704, B*52-Cw*0704 were found as high-risk haplotypes in developing AA in this study. The HLA-A*02 and -A*03 were observed increased frequencies in patients less than 50% hair loss, and HLA-B*27 equally in patients of 50-99% hair loss, alopecia totalis and alopecia universalis. The frequencies of HLA-A*02 and -B*27 were significantly raised in recurrent patients, and ones of HLA-A*02, -A*03 and -B*27 similarly in patients without a positive family history. CONCLUSION: This study demonstrated the positive association of HLA class I alleles and haplotypes with AA. There may be differences in genetic background in patients with different age of onset, grade of scalp hair loss, duration of current attack, a past history and a family history.

Adolescent↗

PubMed2005

Regulating the regulators: control of protein ubiquitination and ubiquitin-like modifications by extracellular stimuli.

Like many other posttranscriptional modifications, ubiquitination and conjugation of ubiquitin-like polypeptides to target proteins are tightly regulated by extracellular stimuli. In many cases, this regulation is dependent upon protein phosphorylation. The regulatory step affected by phosphorylation could involve either recognition of the substrate by an E3 ubiquitin ligase or the actual conjugation reaction. Regulation occurs through phosphorylation of either the substrates or the E3 ligases themselves. This review focuses on recent advances in understanding how extracellular stimuli modulate the attachment of ubiquitin and ubiquitin-like peptides to target proteins.

Animals↗

PubMed2005

[Regulation of orphan receptor ERR alpha by estrogen and progesterone in endometrial carcinoma cell line].

OBJECTIVE: To explore the relationship between expression of ERR alpha mRNA and estrogen and progesterone and to elucidate the function of ERR alpha in endometrial carcinoma. METHODS: The expression of ERR alpha mRNA was examined by reverse transcription polymerase chain reaction. Endometrial carcinoma cell line Ishikawa was dealt with different concentrations of 17beta-estradiol (10(-10) mol/L, 10(-8) mol/L and 10(-6) mol/L) for 15 min, 30 min and 24 h and 17beta-estradiol and ER inhibitor-ICI182780 were given concomitantly to observe the change of ERR alpha mRNA. Different concentrations of progesterone (10(-8) mol/L, 10(-7) mol/L, 10(-6) mol/L and 10(-5) mol/L) were also given to Ishikawa cell line for 24 h to observe the change of ERR alpha mRNA. RESULTS: The expression level of ERR alpha mRNA was slightly higher than that of the control group after being stimulated for 15 min, 30 min and 24 h by 10(-10) mol/L 17beta-estradiol. However the expression level of ERR alpha mRNA was significantly lower than that of the control group after being stimulated for 15 min, 30 min and 24 h by 10(-8) mol/L and 10(-6) mol/L of 17beta-estradiol. When 10(-6) mol/L of ICI182780 and 10(-8) mol/L of 17beta-estradiol were given simultaneously to Ishikawa cell line, this down-regulation was blocked. After being stimulated for 24 h by 10(-7) mol/L, 10(-6) mol/L and 10(-5) mol/L of progesterone, the expression levels of ERR alpha mRNA were significantly higher than that of the control group, but no change was found in 10(-8) mol/L of progesterone. CONCLUSION: 17Beta-estradiol can down-regulate the expression of ERR alpha mRNA and this regulation is mediated by estrogen receptor. Progesterone can up-regulate the expression of ERR alpha mRNA.

Cell Line, Tumor↗

PubMed2005

Clinical presentation of inflammatory bowel disease: a hospital based retrospective study of 379 patients in eastern China.

BACKGROUND: Numerous studies from Europe and North America have provided a wealth of information regarding the epidemiological and clinical characteristics of inflammatory bowel disease (IBD) in Caucasians. Previous studies in mainland China have been limited by small patient numbers or by lack of detailed information about clinical subgroups of the disease. This study was carried out to assess the demographic and clinical characteristics of IBD in Chinese patients. METHODS: In the Sir Run Run Shaw Hospital between 1994 and 2003, 379 patients were diagnosed as IBD. Demographic and clinical data were collected and analysed. RESULTS: Of 379 patients, 317 had ulcerative colitis (UC) (83.6%, 168 male, 149 female, male-female ratio 1.13:1, age range at diagnosis 14-79 years, mean age 44 years) and 62 had Crohn's disease (CD) (16.4%, 39 male and 23 female, male-female ratio 1.70:1, age range at diagnosis 13-70 years, mean age 33 years). In UC, 11.4% of patients had proctitis, 25.2% had proctosigmoiditis, 18.6% were diseased to the splenic flexure and 44.8% had extensive colitis. Nine patients with UC (2.8%) had arthritis, three patients (0.9%) had iritis or conjunctivitis. Of the 62 CD patients, 16 (25.8%) had diseases restricted to the terminal ileum; 15 (24.2%) had colonic diseases; 20 (32.3%) had ileocolonic disease and 11 (17.7%) had disease involving the upper gastrointestinal tract. CONCLUSIONS: This study shows similar characteristics of IBD to that in the West but there are some differences with respect to severity and extraintestinal manifestations. The ethnic and geographic differences may give important clues to the aetiology of IBD.

Adolescent↗

PubMed2005

Multi-detector CT enterography with iso-osmotic mannitol as oral contrast for detecting small bowel disease.

AIM: To assess the feasibility and usefulness of multi-detector CT enterography with orally administered iso-osmotic mannitol as negative contrast in demonstrating small bowel disease. METHODS: Thirteen volunteers and 38 patients with various kinds of small bowel disease were examined. We administered about 1 500 mL iso-osmotic mannitol as negative contrast agent and then proceeded with helical CT scanning on a Siemens Sensation 16 scanner. All volunteers and patients were interviewed about their tolerance of the procedure. Two radiologists post-processed imaging data with MPR, thin MIP, VRT and INSPACE when necessary and then interpreted the scans, and adequacy of luminal distention was evaluated on a four-point scale. Demonstration of features of various kinds of small bowel disease was analyzed. RESULTS: The taste of iso-osmotic mannitol is good (slightly sweet) and acceptable by all. Small bowel distention was excellent and moderate in most volunteers and patients. CT features of many kinds of diseases such as tumors, Crohn's disease,and small bowel obstruction, etc. were clearly displayed. CONCLUSION: Multi-detector CT enterography with iso-osmotic mannitol as negative contrast to distend the small bowel is a simple, rapid, noninvasive and effective method of evaluating small bowel disease.

Administration, Oral↗

PubMed2005

A novel linkage to generalized vitiligo on 4q13-q21 identified in a genomewide linkage analysis of Chinese families.

Generalized vitiligo is a common, autoimmune, familial-clustering depigmentary disorder of the skin and hair that results from selective destruction of melanocytes. Generalized vitiligo is likely a heterogeneous disease, with five susceptibility loci reported so far--on chromosomes 1p31, 6p21, 7q, 8p, and 17p13--in white populations. To investigate vitiligo susceptibility loci in the Chinese population, we performed a genomewide linkage analysis in 57 multiplex Chinese families, each with at least two affected siblings, and we identified interesting linkage evidence on 1p36, 4q13-q21, 6p21-p22, 6q24-q25, 14q12-q13, and 22q12. Subsequently, to extract more linkage information, we investigated our initial genomewide linkage findings in a follow-up analysis of 49 new families and additional markers. Our initial genomewide linkage analysis and our subsequent follow-up analysis have identified a novel linkage to vitiligo on 4q13-q21, with highly significant linkage evidence (a nonparametic LOD score of 4.62 [P=.000003] and a heterogeneity LOD score of 4.01, under a recessive inheritance model), suggesting that 4q13-q21 likely harbors a major susceptibility locus for vitiligo in the Chinese population. We observed a minimal overlap between the linkage results of our current genomewide analysis in the Chinese population and the results of previous analyses in white populations, and we thus hypothesize that, as a polygenic disorder, vitiligo may be associated with great genetic heterogeneity and a substantial difference in its genetic basis between ethnic populations.

China↗

PubMed2005

Identification of a novel mutation in the DSRAD gene in a Chinese pedigree with dyschromatosis symmetrica hereditaria.

Dyschromatosis symmetrica hereditaria (DSH) is an autosomal dominant skin disorder characterized by a mixture of hyperpigmented and hypopigmented macules distributed on the face and dorsal aspects of the extremities that appear in infancy or early childhood. The DSH locus has recently been mapped to chromosome 1q21 and then pathogenic mutations have been identified in the DSRAD gene. In the study reported here we examined the DSRAD gene mutations of a three-generation Chinese pedigree with DSH by direct sequencing. We identified a novel heterozygous nucleotide T-->C transition at position 3388 in exon 14 of the DSRAD gene which induces a C1130R change in the putative deaminase domain of DSRAD. Our study expands the database on the DSRAD gene mutations in DSH and enriches the knowledge about the function of the DSRAD gene.

Adenosine Deaminase↗

PubMed2005

Role of NF-kappaB signaling in hepatocyte growth factor/scatter factor-mediated cell protection.

The cytokine scatter factor/hepatocyte growth factor (HGF/SF) protects epithelial, carcinoma, and other cell types against cytotoxicity and apoptosis induced by DNA-damaging agents such as ionizing radiation and adriamycin (ADR, a topoisomerase IIalpha inhibitor). We investigated the role of nuclear factor kappa B (NF-kappaB) signaling in HGF/SF-mediated protection of human prostate cancer (DU-145) and Madin-Darby canine kidney (MDCK) epithelial cells against ADR. HGF/SF caused the rapid nuclear translocation of the p65 (RelA) subunit of NF-kappaB associated with the transient loss of the inhibitory subunit IkappaB-alpha. Exposure to HGF/SF caused the activation of an NF-kappaB luciferase reporter that was blocked or attenuated by the expression of a mutant 'super-repressor' IkappaB-alpha. Electrophoretic mobility shift assay supershift assays revealed that HGF/SF treatment induced the transient binding of various NF-kappaB family proteins (p65, p50, c-Rel, and RelB) with radiolabeled NF-kappaB-binding oligonucleotides. The HGF/SF-mediated protection of DU-145 and MDCK cells against ADR (demonstrated using MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assays) was abrogated by the IkappaB-alpha super-repressor. The ability of HGF/SF to activate NF-kappaB signaling was dependent on c-Akt --> Pak1 (p21-associated kinase-1) signaling (with Pak1 downstream of c-Akt) and was inhibited by the tumor suppressor PTEN (phosphatase and tensin homolog). Inhibitors of phosphatidylinositol-3'-kinase and Src family kinases significantly inhibited HGF/SF-mediated activation of NF-kappaB, while inhibitors of MEK, protein kinase C, and p70 S6 kinase had a modest effect or no effect on NF-kappaB activity. HGF/SF induced the expression of several known NF-kappaB target genes (cIAP-1 (cellular inhibitor of apoptosis-1), cIAP-2, and TRAF-2 (TNF receptor-associated factor-2)) in an NF-kappaB-dependent manner; HGF/SF blocked the inhibition of expression of these genes by ADR. Experimental manipulation of expression of these genes suggests that they (particularly TRAF-2 and cIAP-2) contribute to the protection against ADR by HGF/SF. These findings suggest that HGF/SF activates NF-kappaB through a c-Akt --> Pak1 signaling pathway that is also dependent on Src, and that NF-kappaB contributes to HGF/SF-mediated protection against ADR.

Active Transport, Cell Nucleus↗

PubMed2005

Two frameshift mutations in the RNA-specific adenosine deaminase gene associated with dyschromatosis symmetrica hereditaria.

OBJECTIVE: To report and analyze the mutations of the double-stranded RNA-specific adenosine deaminase (DSRAD) gene in 2 Chinese pedigrees with dyschromatosis symmetrica hereditaria (DSH). DESIGN: Pedigree study. SETTING: Anhui province of China. PATIENTS: Two Chinese families, consisting of 19 individuals (family 1) and 5 individuals (family 2). INTERVENTIONS: We directly performed mutation detection of the DSRAD gene in 2 Chinese families with DSH by sequencing. The whole coding region of DSRAD was amplified by polymerase chain reaction, and products were analyzed by direct sequencing. MAIN OUTCOME MEASURES: Frameshift DSRAD gene mutations. RESULTS: The c.3513insC (Arg1171fs) mutation was found in all patients but not in the healthy individuals from family 1, and the c.3220_3224delGCATC (Gly1073fs) mutation was found in 2 patients but not in the healthy members of family 2. These 2 mutations were not found in 96 unrelated control individuals. CONCLUSION: Our data suggest that these 2 novel frameshift mutations in the DSRAD gene could cause DSH in the Chinese Han population and add new variants to the repertoire of DSRAD mutations in DSH.

Adenosine Deaminase↗

PubMed2005

The mortality rate from anorexia nervosa.

OBJECTIVE: We determined the standardized mortality ratio (SMR) in our anorexia nervosa (AN) patient population. METHOD: We used a cross-sectional design to study an inception cohort (1981-2000) drawn from the provincial tertiary care eating disorders program at St. Paul's Hospital (British Columbia, Canada). All patients who completed their initial assessment for an eating disorder were included in the study. Vital status, date and cause of death from British Columbia Vital Statistics Agency, date of assessment, date of birth, and diagnosis at the time of assessment were collected for each patient. RESULTS: Of 954 patients, 326 diagnosed with AN completed an assessment over the 20 years. The SMR was 10.5 (95% confidence interval [CI] = 5.5-15.5) for AN. DISCUSSION: Some studies in the literature report that AN has the highest mortality rate of any psychiatric disorder in young females. However, others dispute this fact and report an SMR lower than the normal population mortality (SMR = 0.71). Contrary to some reports in the literature, our study confirms a high mortality rate within the AN population.

Adult↗

PubMed2005

Identification of a novel locus for Marie Unna hereditary hypotrichosis to a 17.5 cM interval at 1p21.1-1q21.3.

Marie Unna hereditary hypotrichosis (MUHH) is a rare autosomal dominant disorder characterized by coarse, wiry, twisted hair developed in early childhood and followed by the development of alopecia. A locus for this disorder was localized to chromosome 8p, but no gene responsible for it has been identified. To map and determine whether MUHH is a genetically heterogeneous disorder and identify the disease gene locus in a four-generation Chinese family with MUHH. We performed a genome-wide scan in this family. Two-point linkage analysis was performed using Linkage programs version 5.10 software and haplotype was constructed with Cyrillic Version 2.02 software. We failed to confirm the previous locus for MUHH at chromosome 8p and obtained the conformed evidence for linkage at chromosome 1. Two-point logarithm of odds ratio scores > or =3 were observed at markers D1S2746 and D1S2881. Haplotype analysis localized this locus to a 42 Mb region. The previous results and this study have shown that MUHH is a genetically heterogeneous disorder. Our family was mapped to a 17.5 cM region between markers D1S248 and D1S2345.

Adult↗

PubMed2005

Association of HLA-DQA1 and DQB1 genes with vitiligo in Chinese Hans.

BACKGROUND: Vitiligo is an acquired depigmentary disorder of the skin and hair which results from selective destruction of melanocytes. Serological typing and genotyping of human leukocyte antigen (HLA) have shown discrepancies in HLA associations with vitiligo in different ethnic populations. METHODS: Polymerase chain reaction sequence-specific primer (PCR-SSP) method was used to analyze the distribution of HLA-DQA(1) and -DQB(1) alleles among 187 patients with vitiligo and 273 healthy controls through Epi Info version 6 package (Centers for Disease Control and Prevention, Atlanta, GA, USA). RESULTS: The frequencies of HLA-DQA1*0302 (OR = 1.98, P(c) < 0.01), -DQB1*0303 (OR = 3.14, P(c) < 0.001), and -DQB1*0503 (OR = 3.36, P(c) < 0.05) alleles were significantly increased in patients with vitiligo compared with controls, and HLA-DQA(1)*0501 (OR = 0.40, P(c) < 0.01) allele frequency was highly decreased. HLA-DQA1*0302 (OR = 5.19, P(c) < 0.001), -DQA1*0601 (OR = 2.95, P(c) < 0.05), -DQB1*0303 (OR = 4.50, P(c) < 0.001), and -DQB1*0503 (OR = 6.69, P(c) < 0.001) alleles were positively associated, whereas HLA-DQA1*0501 (OR = 0.05, P(c) < 0.001) allele was negatively associated with childhood vitiligo patients, and HLA-DQB1*0303 (OR = 2.76, P(c) < 0.001) allele was positively associated with adult vitiligo patients compared with controls. The frequency of HLA-DQB1*0303 (OR = 3.72, P(c) < 0.001) allele was significantly increased in localized vitiligo patients vs. controls, whereas HLA-DQA1*0302 (OR = 2.47, P(c) < 0.01), -DQB1*0303 (OR = 2.67, P(c) < 0.01), and -DQB1*0503 (OR = 4.46, P(c) < 0.01) allele frequencies were significantly increased and -DQA1*0501 (OR = 0.27, P(c) < 0.01) allele frequency was highly decreased in generalized vitiligo patients. CONCLUSIONS: HLA-DQA1*0302, -DQA1*0601, -DQB1*0303, and -DQB1*0503 alleles could be susceptible alleles of vitiligo, while HLA-DQA1*0501 allele could be a protective allele in Chinese Hans. There may be different genetic backgrounds between vitiligo patients of childhood and adult, localized and generalized.

Adolescent↗

PubMed2005

Use of physiologic pacing after the Canadian trial of physiologic pacing.

The Canadian trial of physiologic pacing (CTOPP), published in 2000, demonstrated a reduction in atrial fibrillation (AF), stroke and death with preservation of atrioventricular synchrony, though only the lower rate of AF was statistically significant. The purpose of this study was to determine the effect of CTOPP on pacing mode selection in our region. The British Columbia Cardiac Registry contains prospectively entered data covering a population of 4 millions (M) and 17 implanting centers. It was examined for mode selection trends from 1997 to 2002. At examination, there were data on 22,446 pulse generators (PG) and 29,898 leads. New implant rates per M population were 1997:473; 1998:456; 1999:505; 2000:513; 2001:486; 2002:510. PG replacements also increased, resulting in a total implant rate of 667 PG per M in 2002. Over the 6-year period, DDD use decreased from 321 to 306, but DDDR use, more than doubled from 317 to 750 PG/year. VVI use steadily decreased from 741 to 410 PG/year, while VVIR use increased more modestly from 1997 to 1999, then remained stable. During the 6-year period bracketing CTOPP, use of modes maintaining AV synchrony increased by over 32%, to 53% of PG implanted in 2002. Our PG implant rate was much higher than expected from prior retrospective surveys, and similar to rates in Belgium, France, and Germany. CTOPP did not decrease our use of physiologic pacing but, instead, was associated with a brief pause, then progressively increased in both academic and community centers. Patients' need and widely accepted standards of care proved more important in clinical decision making than the results of a flawed randomized trial.

British Columbia↗

PubMed2005

Development of a cell-based high-throughput specificity screen using a hepatitis C virus-bovine viral diarrhea virus dual replicon assay.

The hepatitis C virus (HCV) replicon is a unique system for the development of a high-throughput screen (HTS), since the analysis of inhibitors requires the quantification of a decrease in a steady-state level of HCV RNA. HCV replicon replication is dependent on host cell factors, and any toxic effects may have a significant impact on HCV replicon replication. Therefore, determining the antiviral specificity of compounds presents a challenge for the identification of specific HCV inhibitors. Here we report the development of an HCV/bovine viral diarrhea virus (BVDV) dual replicon assay suitable for HTS to address these issues. The HCV reporter enzyme is the endogenous NS3 protease contained within the HCV genome, while the BVDV reporter enzyme is a luciferase enzyme engineered into the BVDV genome. The HTS uses a mixture of HCV and BVDV replicon cell lines placed in the same well of a 96-well plate and isolated in the same cell backgrounds (Huh-7). The format consists of three separate but compatible assays: the first quantitates the amount of cytotoxicity based upon the conversion of Alamar blue dye via cellular enzymes, while the second indirectly quantitates HCV replicon replication through measurement of the amount of NS3 protease activity present. The final assay measures the amount of luciferase activity present from the BVDV replicon cells, as an indicator of the specificity of the test compounds. This HCV/BVDV dual replicon assay provides a reliable format to determine the potency and specificity of HCV replicon inhibitors.

Animals↗

PubMed2005

Replication-competent chimeric hepatitis C virus subgenomic replicons.

OBJECTIVE: To utilize chimeric hepatitis C virus (HCV) replicons to select adaptive mutation(s) that allow replication of a genotype 1a replicon. METHODS: We used a genetic approach to gradually apply selective pressure by generating chimeric replicons through sequential replacement of nonstructural genes of a 1b replicon with genotype 1a sequences. RESULTS: A chimeric replicon containing a genotype 1a NS5A protein did not replicate in a transient assay, but could be used to establish stable cell lines using G418 selection. The cell lines contained a K1846T mutation in NS4B which functioned as an adaptive mutation that now allowed the chimera to replicate at levels similar to wild-type replicons. Similarly, replication of a 1a NS5A5B chimera was only observed after establishment of stable cell lines, even in the presence of the K1846T mutation. Sequence analysis of this cell line revealed an additional adaptive mutation of M1496L in NS3. Lastly, by including the K1846T mutation in a replicon that was entirely genotype 1a sequence, stable 1a cell lines could be established. CONCLUSION: These studies identify an NS4B adaptive mutation, K1846T, which allows establishment of a replication-competent 1a replicon and demonstrate the utility of this chimeric approach for establishing replicons for various HCV genotypes.

Amino Acid Substitution↗

PubMed2005

[NOD2/CARD15 gene polymorphisms and susceptibility to Crohn's disease in Chinese Han population].

OBJECTIVE: Previous studies have shown NOD2/CARD15 gene is the first susceptibility gene to Crohn's disease (CD), three single nucleotide polymorphisms (SNPs) of the gene have been identified to be associated with CD in the Caucasians, but not in the Japanese. Here we have evaluated the NOD2/CARD gene polymorphisms in Chinese patients to determine whether the gene is associated with susceptibility to CD in Chinese Han population. METHODS: Blood samples were obtained from 32 patients with CD, 110 patients with ulcerative colitis, and 292 healthy controls in Zhejiang location. Genotyping for 3 common NOD2/CARD15 (Arg702Trp, Gly908Arg, Leu1007fsinsC) polymorphisms was carried out using polymerase chain sequence with specific primer. RESULTS: None of the patients with CD had heterozygous or homozygous SNPs variants. Similarly none of the ulcerative colitis or health controls. CONCLUSION: The common variants in NOD2/CARD15 found in Caucasians with CD are not associated with CD in the Chinese Han population.

Adult↗