Establishment of a tight tetracycline-controlled HCV-C double transgenic mouse model / 南方医科大学学报

<p><b>OBJECTIVE</b>To develop a tight tetracycline-controlled HCV-C double transgenic mouse model.</p><p><b>METHODS</b>By crossbreeding of ApoE-rtTA-tTS transgenic mice with TRE-HCV-C transgenic mice, the double transgenic mice were produced in the F1 generation. The presence of HCV-C and tTS gene in the F1 generation was confirmed by PCR, followed by further identification and quantification of the transgene using Southern blot hybridization. The expression of HCV-C in the liver of the mouse model was detected immunohistochemically.</p><p><b>RESULTS AND CONCLUSION</b>Two transgenic mice were obtained, which contained ApoE-rtTA-tTS and TRE-HCV-C genes in the genome. Five founders contained HCV-C gene as confirmed by PCR and Southern blot hybridization. The tight tetracycline-controlled system may facilitate further study of HCV-C gene expression and gene therapy of hepatic cellular carcinoma.</p>

Study on molecular epidemiology of Mycobacterium tuberculosis in Chinese army with PCR amplified fingerprinting methods / 中华流行病学杂志

<p><b>OBJECTIVE</b>Typing of Mycobacterium tuberculosis strains and epidemiological studies in the army of southern China to provide scientific basis for prevention of pulmonary tuberculosis.</p><p><b>METHODS</b>A rapid fingerprinting of M. tuberculosis strains method by polymerase chain reaction (PCR) with outward-directed primers that designed to the ends of the insertion sequence IS6110 was developed, and to analyze the relationship between the polymorphism of DNA fingerprinting and epidemiology of M. tuberculosis.</p><p><b>RESULTS</b>One hundred and fifty-four M. tuberculosis detected were classified into eight types according to their characters of PCR amplified fingerprints. The main types were type I (36.4%), type II (31.8%), and type III (21.4%), while other types were less than 4 percentage. In those main type groups, patients aged 20 to 29 and 30 to 39 took up 31.8% and 27.9% respectively. For those main types, the distribution of those types in the first treated patients showed significant difference compared with that in the retreated patients, and the rate of drug-resistance was also statistically different. However, the distribution was not statistically significant to history of BCG vaccination and patients living in urban or rural area. The main drug-resistant strains were only Isoniazid-resistant or Rifampin-resistant strains, while the drug-resistant strains were 44.4%, 29.6% and 14.8% respectively in type I, type II and type III.</p><p><b>CONCLUSION</b>PCR fingerprinting was a rapid, precise, sensitive, specific method to type M. tuberculosis, and could be used to study the epidemiology of tuberculosis; The prevalence of tuberculosis was primarily due to the transmission of type I, type II and type III in the army being studied from Southern China, to suggest that surveillance needs to be strengthened.</p>

Study on DNA fingerprinting of Mycobacterium tuberculosis strains isolated in Southern Chinese army by IS6110-restriction fragment length polymorphism / 中华流行病学杂志

<p><b>OBJECTIVE</b>To study the correlation between DNA fingerprinting of Mycobacterium tuberculosis (MTB) stains isolated from the Chinese army in the south and from local residents, and to investigate the molecular epidemiological characteristics of tuberculosis (TB) in the army, for the sake of TB prevention in the army.</p><p><b>METHODS</b>MTB DNA was digested with restriction endonuclease PvuII and electrophoresed in agarose gel, after Southern Blotting, the membrane was hybridized with a 245 bp fragment of IS6110 which labeled [alpha(32)P]-dCTP as probe. Finally, a restriction fragment length polymorphism (RFLP) patterns was shown, and analyzed logestic with epidemiological data from the patients.</p><p><b>RESULTS</b>A total number of 185 TB strains were detected and the IS6110 copy numbers ranged from 1 - 22. No significant difference was found in the IS6110 copy numbers between patients from army and local patients. IS6110 copy numbers of TB strains in army patients were centered in 6 - 20, however, with 7 - 20 copies in local TB patients. The TB strains were dispersed into 8 groups and the majority of TB strains in both army and local patients was centered in groups I, II, III. The distribution of DNA fingerprint for drug resistance TB strains was significantly different from those for sensitive strains. No different distribution of among groups was found regarding BCG history.</p><p><b>CONCLUSIONS</b>The genetics of TB stains were roughly the same between the army patients and local ones, but there was a strong correlation in the gene levels. Data suggested that a close connection should be considered on TB prevention and treatment for TB patients in the army and local residents.</p>