In the present study the bioavailability of selenium in Se-yeast was compared with that in sodium selenite to rats fed on low-Se diet from a keshan discaes area. The bioavailability of selenium in Se-yeast when estimated by heart, liver kidney and erythrocyte Se contents was significantly greater than that in selenite at wk 2 and 4 of supplement, indicating that selenium in Se-yeast is more cfficiently retained in tissues than selenite selenium. When the criterion used was either platelet or liver glutathione peroxidase (GSH_(?)) activity, the bioavailability was lower for selenium in Se-yeast than for in selenite at wk 2, but higher at wk 4, showing that selenium from both selenite and Se-yeast is clearly available for GSH_(?), synthesis, "although Se-yeast restores GSH_(?) activity more slowly. In addition, the effect of selenium in Se-yeast in maintaining cither Se levels in heart and erythrocyte or GSH_(?) activities in platelets and liver was superior to that of selenite after the selenium supplements were withdrawn.

Objective To explore the diagnostic value of contrast-enhanced spiral CT after low tension and drinking water in papillary carcinoma of ampulla. Methods CT manifestations of papillary carcinoma of ampulla comfirmed pathologically in 20 cases were analysed retrospectively emphasized in artery phase on contrast CT which was performed after injecting 654-2 20 mg and drinking 300~500 ml water.Results Of all the cases , only 2 cases showed tumor filling defect in the descending part of duedenum nearby pancreas on routine CT, but all the cases showed more or less tumor filling defect on contrast-enhanced spiral CT . The diameters of the tumor were between 0.8 to 2.6 cm,2 cases with head of pancreas affected,the diameters of the tumor were between 2.4 to 2.6 cm.There were 2 cases with lymph node metastasis nearby duedenum.All the cases showed expansion of gallbladder ,intrahepatic duct and choledochus expanding in the liver. Conclusion Contrast-enhanced spiral CT after low tension and drinking water is superior to routine CT in determining the size and morphosis of tumor.

Objective To study the difference of image quality and radiation dose between different exposure modes with full-field digital mammography (FFDM).Methods The Fluke18-220mammographic phantom was exposed by FFDM system with different exposure modes at automatic exposure control ( AEC ) ,including contrast mode,standard mode and dose mode,and the exposure factors and radiation dose were recorded.The images on monitor with the best window width and window level were read by four independent radiologists.The images of specks groups,nylon fibers and masses was assessed by the four experienced readers at the criterion of American College of Radiology.Results The detection of specks groups,nylon fibers and masses were statistically different at the contrast mode and standard mode (F =41.321,P ＜ 0.05),further at the contrast mode and dose mode.The detection of specks groups、nylon fibers and masses were not statistically different( P ＞ 0.05 ) at standard mode and dose mode,but the radiation doses were different.The ESD at standard mode and dose mode was 4.5 and 3.15 mGy,respectively.The AGD of standard mode and dose mode was 1.18 mGy and 0.78 mGy,respectively.Conclusions The standard mode and dose mode of FFDM might be fit for most patients,especially at the dose mode.Contrast mode of FFDM should be strictly controled in use.

Objective To evaluate the performance of DNA microarray for rapid detection resistance to rifampin and isoniazid in Mycobacterium tuberculosis clinical isolates and identify suitable target sites for molecular genetic test.Methods Twenty-four clinical Mycobacterium tuberculosis isolates were collected retrospectively from Shenzhen Center for Chronic Disease Control in 2009 and 127 isolates from project on anti-tuberculosis drug resistance surveillance in Shenzhen during 2007 to 2009.Drug susceptibility to rifampin and isoniazid of the stains were determined by DNA microarray,and results were compared to that obtained with reference proportion method drug susceptibility testing for sensitivity,specificity and accuracy.The consistency of microarray and phenotypic susceptibility testing was evaluated by Kappa test.Genetic mutations in rpoB,katG,inhA,regulatory region of inhA,and regulatory region of ahpC were investigated by DNA sequencing to assess proper loci for rapid molecular diagnosis.Results Compared against results of proportion method,the sensitivity,specificity and accuracy of the DNA microarray assay for rifampin resistance were 94.4％,97.5％ and 96.0％ respectively,and for isoniazid resistance were 79.1％,100％ and 86.8％ respectively.Mutations in resistance-determining region of rpoB were observed in 97.2％ (70/72) of the isolates resistant to rifampin,which contributed in the 531,526,516,511 and 533codon region.Mutations in katG315 codon,inhA-15,and ahpC regulatory region were found in 70.3％ (64/91),11.0％ (10/91) and 9.9％ (9/90) of the isolates resistant to isoniazid,respectively.Mutations of ahpC promoter region consists of ahpC-9 (4 strains),ahpC-10 (2 strains),ahpC-6 (2 strains),ahpC-12 (1 strain),and ahpC-32 (1 strain).Conclusions DNA microarray provided a rapid method for the detection of drug-resistant Mycobacterium tuberculosis isolates,and demonstrated good performance except less sensitive for isoniazid resistance.The mutations in ahpC regulatory region might be good target loci for detection of isoniazid-resistant Mycobacterium tuberculosis,so screening the region may significantly improve the sensitivity for molecular genetic tests.

Objective:To assess the prevalence of HIV primary drug resistance and drug resistance gene mutations among men who have sex with men (MSM).Methods:We searched eight electronic databases (CNKI,VIP,CBM,Wanfang Database,PubMed,Web of Knowledge,Springer,Medline) for the studies of HIV drug resistance relevant to MSM.Drug resistance and drug resistance mutations data were pooled and analyzed according to statistical test of homogeneity.Subgroups were further divided according to sample size,location,race,quality rating score,sampling time.Results:Forty-three studies were included in this Meta-analysis.The pooled rate of total to protease inhibitor (PI),nucleoside reverse transcriptase inhibitor(NRTI) or non-nucleoside reverse transcriptase inhibitor (NNRTI) were 10.21％ (95％ CI 8.65％ to12.03％),2.98％ (95％ CI 2.25％ to 3.93％),4.05％ (95％ CI 3.14％ to 5.21％),4.42％ (95％ CI 3.31％ to 5.88％),respectively.The pooled rates of PI major mutation,PI secondary mutations,NRTI mutations and NNRTI mutations were 0.55％ (95％ CI 0.38％ to 0.80％),1.31％ (95％ CI 0.98％ to 1.75％),0.85％ (95％ CI 0.51％ to 1.40％),1.19％ (95％ CI 0.70％ to 2.01％),0.79％ (95％ CI 0.55％ to 1.13％),1.73％ (95％ CI 1.21％ to 2.46％),0.86％ (95％ CI 0.61％ to 1.21％),2.24％ (95％ CI 1.77％ to 2.83％),respectively.Sample size,region,and race were heterogeneous sources;the rate of resistance mutations and gene mutation rate were different in different subgroups.Conclusion:The prevalence of primary drug resistance among MSM was high in Americas and Europe,and it was gradually increased in Asia.We should pay attention to the high incidence of PI secondary mutations.

Objective To evaluate the usefulness of mycolic acid for identification of Mycobacterium species using SMIS. Methods One hundred and eighteen clinical Mycobacterium isolates collected from Beijing Tuberculosis and Thoracic Tumor Research Institute through whole year of 2007 were analyzed. The 118 isolates contain 25 isolates of Mycobacterium tuberculosis and 93 non tuberculosis Mycobacterium identified by PNB method. Mycolic acid analysis using SMIS is evaluated for identification of a broad range of Mycobacteria in comparison with 16S rDNA , 16-23S rDNA ITS sequencing to measure the concordance rate and agreement, and verify the concordance rate and agreement among results of mycolic acid, sequencing and PNB in identifying Mycobacterium tuberculosis and non tuberculosis Mycobacterium. Results The concordance rate between mycolic acid method analysis and DNA sequencing is 92% ( 108/118), of which concordance rate in Mycobacterium tuberculosis complex and non tuberculosis Mycobacterium are 95% (35/37) and 90% (73/81) respectively, agreement of both is great( agreement Kappa value is 0. 96). Through retrospective analysis, the concordance of results between SMIS and PNB method analysis is 90% (106/118)and agreement is well( agreement Kappa value is 0. 73 ), the concordance of results between sequencing and PNB method analysis is also 90% ( 106/118 ) and agreement is well (agreement Kappa value is 0. 74 ),despite the identification results of 11 isolates by PNB method are discordant. Conclusion Mycolic acid analysis by SMIS enables rapid identification of a broad range of clinical Mycobacterium species, which could play an important role in polyphasic identification of Mycobacterium species.

Objective To evaluate a rapid biochip system for the determination of muhidrugresistant tuberculosis (MDR-TB) in Mycobacterium tuberculosis isolates. MethodsA total of 1 186 clinical strains, including 800 rifampin (RFP) resistant isolates, 797 isoniozid (INH)resistant isolates, 791 MDR-TB and 380 susceptible strains, were selected from Beijing Chest Hospital, Shanghai Pulmonary Hospital and Guangzhou Chest Hospital respectively using stratified sampling method. Biochips were used to detect loci of rpoB 511 (T→C), 513 (A→C, C→A), 516 (G→T, A→T, A→G) , 526 (C→T, C→G, A→T, A→G), 531 (C→T, C→G), 533 (T→C), katG 315 ( G→C, G→A) and inhA -15 (C→T). Absolute concentration drug susceptibility test of RFP and INH were performed to serve as the gold standard to calculate susceptibility, specificity and overall concordance of biochip test. All polymerase chain reaction (PCR) products were sequenced to confirm the mutations. ResultsThe concordances between the biochip system and absolute concentration drug susceptibility test were 93.7％ ( 1 108/1 183 ) for RFP, 83. 8％(994/1 186) for INH and 82.4％ (975/1 183) for MDR-TB. Compared with absolute concentration drug susceptibility test, the biochip method displayed a sensitivity of 92. 0％ (733/797) and 77. 4％ (617/797)and a specificity of 97. 2％ (375/386) and 96. 9％ (377/389) for RIF and INH, respectively. For MDR-TB, the biochip system reached a sensitivity of 74. 6％ ( 588/788 ) and a specificity of 98.0％ ( 387/395 ).Among rpoB mutants, mutations were mostly detected at codon 531[64. 5％ (480/744)]. In stains with mutations in katG or inhA, 77.4％ ( 487/629 ) had mutation at codon 315 ( TCG ) of katG only. The sequencing results had a high concordance with that of the biochip method. There were slight differences in 5 strains, among which one strain was detected by biochip as katG 315(G→C) mutant, but was identified by sequencing as wild type, and mutation types other than those detected by the biochip were confirmed in the other 4 strains by sequencing. Conclusion This biochip system is adapted for extensive application in clinical diagnosis, as it allows fast and reliable detection of resistance to isoniazid and rifampin in tuberculosis clinical isolates.

Objective To study the genotypes of representative Mycobacterium tuberculosis (M.tuberculosis) strains from China with spacer oligonucleotide typing (spoligotyping),and to investigate the prevalence of different genotypes TB in China,and analyse the relationship between genotype and drug resistance.Methods 4017 clinical isolates were collected by Chinese Center for Disease Control and Prevention from 2007 to 2008 in 31 provinces in China according to sampling principle of epidemiology.Drug susceptibility testing was performed using proportion method,and spoligotyping was chosen to carry out genotyping of these M.tuberculosis.In addition,chi-square test was used to compare the differences among the detection rate of different genotypes.Results Among the 4017 M.tuberculosis isolates,2500 ( 62.2％ ) isolates belonged to Beijing genotype.The percentage of Beijing genotypes in the northern of China was higher than that in the southern of China ( 76.5％ vs.53.2％,x2 =219.69,P ＜ 0.05 ),while T1 genotypes were more common in the southern China,compared with that in northern China ( 13.3％ vs.4.3％,x2 =219.69,P ＜ 0.05 ).The differences were statistically significant.The proportions of Rifampinresistant (21.7％ vs.21.7％ ),Ofloxacin-resistant (4.9％ vs.2.4％ ) and Multidrug-resistant ( 11.3％vs.7.4％ ) isolates among Beijing genotype strains were significantly higher than those among non-Beijing strains (x2 =22.10,14.42 and 14.83,respectively,P ＜ 0.05 ).Conclusions Beijing genotype was still predominant epidemic genotypes.The percentage of Beijing genotype showed difference between distinct areas,and the percentage of Beijing genotypes in northern China was higher than that in southern China.Beijing genotype strains reveal correlation with Rifampin-resistance,Ofloxacin-resistance and Multidrug-resistance.

Objective To understand the prevalence rate of genital Chlamydia trachomatis among a population with suspected-Neisseria gonorrhoeae infection,the distribution of Chlamydia trachomatis genotypes,assess changes in omp1 sequences among patients with Neisseria gonorrhoeae and Chlamydia trachomatis coinfections.Methods Four hundred and one swabs were collected.Chlamydia trachomatis and Neisseria gonorrhoeae were detected by Roche Amplicor System.DNA were extracted from those samples and were amplified by nested PCR.PCR products were sequencing and analyzed by software Mega4.0.Results The prevalence of genital Chlamydia trachomatis infection,Neisseria gonorrhoeae infection and coinfection with genital gonorrhoea and genital chlamydia were 82.3%,24.2% and 21.7% each.Eight genotypes were identified in 73 sequences,including E(27.4%),G/Ga(23.3%),D/Da(16.4%),F(13.7%),J (11.0%),H(5.5%),B and K(each 1.4%).Sequencing analysis showed that 3 cases(4.1%) had missense mutation,including genotype D/Da,E,G/Ga.Genotypes F,H,J and K were more variable,however,most of them were silent mutation.Conclusion The prevalence rate of genital Chlamydia trachomatis among a population with Neisseria gonorrhoeae infection was high.The most common genotypes were genotype E,G/Ga,D/Da and F; Sequencing analysis has provided a tool for the molecular epidemiology of genital Chlamydia trachomatis infections.

Objective To determine vascular endothelial growth factor(VEGF)-460 gene polymorphism in Uyghurs and its relationship to urolithiasis in south Xinjiang. Methods Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP),gene sequencing and genetic analysis methods were used in 200 urolithiasis patients of Uyghurs, and 200 healthy Uyghurs. Results The distribution of genotype and allele had no significant difference between urolithiasis patients and normal controls (P＞0. 05). The frequencies for the CC,TT and CT genotypes in patients with urolithiasis and normal controls were 1.5 %, 29.0 %, 69.5 % and 0. 5 %, 27.5 %, 72.0 %, respectively. The frequencies for C and T allele were 36.2%,63.7% and 36.9% ,63.1%, respectively. Conclusions The results of VEGF-460 gene polymorphisms indicate no significant relationship between patients with turolithiasis and normal controls in Uyghurs in south Xinjiang,which may not be urolithiasis susceptibility genetic locus.