Construction of standard plasmids for detecting Salmonella in meat products with real-time fluorescence quantitative polymerase chain reaction / 上海预防医学

Objective To construct standard plasmids for detecting Salmonella in meat products with real-time fluorescence quantitative polymerase chain reaction(PCR).Methods Primers directed at Salmonella invA gene were designed.Specific fragments were amplified and cloned into plasmid vectors to construct recombinant plasmids.The constructed recombinant plasmids were used as standards for implementing the real-time fluorescence quantitative PCR after optimization, establishing standard curves and examining the sensitivity and stability of these standards.Results The plasmid standard containing the invA gene in Salmonella was successfully constructed.The cycle threshold value(Ct value) of the standard curve established by means of the plasmid standard and the number of template copies exhibited good linear relationship(r2=0.9979).The minimum that could be detected by means of this method was 10 copies/reaction.The standard plasmid was proved to have good stability.This standard plasmid was used to detect Salmonella in meat products.After two hours enrichment, sample detection could be completed within seven hours.Conclusion The constructed plasmid standard can be used for detecting Salmonella in meat products by means of the fluorescence quantitative PCR, which can provide reliable reference bases for examining quality of relevant experiments.

Plasticity of regulation of mannitol phosphotransferase system operon by CRP-cAMP complex in Vibrio cholerae / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>The complex of the cyclic AMP receptor protein (CRP) and cAMP is an important transcriptional regulator of numerous genes in prokaryotes. The transport of mannitol through the phosphotransferase systems (PTS) is regulated by the CRP-cAMP complex. The aim of the study is to investigate how the CRP-cAMP complex acting on the mannitol PTS operon mtl of the Vibrio cholerae El Tor biotype.</p><p><b>METHODS</b>The crp mutant strain was generated by homologous recombination to assess the need of CRP to activate the mannitol PTS operon of V. cholerae El Tor. Electrophoretic mobility shift assays (EMSA) and the reporter plasmid pBBRlux were used to confirm the role that the CRP-cAMP complex playing on the mannitol PTS operon mtl.</p><p><b>RESULTS</b>In this study, we confirmed that CRP is strictly needed for the activation of the mtl operon. We further experimentally identified five CRP binding sites within the promoter region upstream of the mannitol PTS operon mtl of the Vibrio cholerae El Tor biotype and found that these sites display different affinities for CRP and provide different contributions to the activation of the operon.</p><p><b>CONCLUSION</b>The five binding sites collectively confer the strong activation of mannitol transfer by CRP in V. cholerae, indicating an elaborate and subtle CRP activation mechanism.</p>

Stereotactic body radiation therapy favors long-term overall survival in patients with lung metastases: five-year experience of a single-institution / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Metastatic lung cancer is one of the most common oncologic problems. This study aimed to evaluate the long-term clinical outcome of stereotactic body radiation therapy (SBRT) for metastatic lung tumors.</p><p><b>METHODS</b>We retrospectively reviewed the 71 patients with lung metastases, who had 172 lesions treated with SBRT from January 2000 to December 2006. All patients were unfit or failed after surgery and/or chemotherapy. The median total dose was 48 Gy (range, 30 - 60) in 4 (range, 2 - 12) fractions. The median size of the irradiated lesions was 2.1 cm (range, 0.9 - 7.9 cm).</p><p><b>RESULTS</b>All but two patients received follow up. The median follow-up time was 24.7 months (range, 2.9 - 114.4 months). The median follow-up time for living patients was 86.8 months (range, 58.1 - 114.4 months). The 1-, 3-, 5-year local control and overall survival rates were 88.8%, 75.4%, 75.4% and 78.9%, 40.8%, 25.2%. Multivariate analysis showed that the absence of extrapulmonary metastases (P = 0.024; hazard ratio (HR), 1.894; 95% confidence interval (CI), 1.086 - 3.303) and disease-free interval ≤ 12 months (P = 0.014; HR, 0.511; 95%CI, 0.299 - 0.873) were independent prognostic factors. No grade 3 or more acute and late toxicities occurred. Only one patient developed a non-symptomatic rib fracture.</p><p><b>CONCLUSION</b>SBRT could be an alternative treatment to surgery for subsets of patients with lung metastases with favorable long-term survival and tolerable complications.</p>

Test of dose distribution of palatal denture applicator containing (125)I seeds / 中华口腔医学杂志

<p><b>OBJECTIVE</b>to measure the dose distribution (tissue absorbed dose) of palatal denture applicator containing (125)I.</p><p><b>METHODS</b>simulated model of head and neck was used to wear the palatal dental applicator containing (125)I for the postoperative brachytherapy of a simulated tumor at a diameter of 2 cm in the palate. The denture contained 11 (125)I seed with radioactivity of 29.6 MBq per seed. The prescribed dose (edge matched dose) was 80 Gy. The absorbed dose in the simulated target and its adjacent area was measured by thermoluminescence dosimeters.</p><p><b>RESULTS</b>the dose in the target area reached the value of treatment needs, and the dose absorbed by tissue around the target was lower except tongue.</p><p><b>CONCLUSIONS</b>using palatal denture applicator containing (125)I for postoperative brachytherapy of malignant tumors of palate can get satisfied dose distribution, but the tongue needs to be protected.</p>

The technic and dose evaluation of postoperative (125)I radioactive seeds brachytherapy for malignant tumors of maxilla / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To evaluate the technique and effect of treating malignant tumors of maxilla with postoperative brachytherapy by digital model obturators containing (125)I radioactive seeds.</p><p><b>METHODS</b>Four patients with adnoid cystic carcinomas and two with squamous cell carcinomas in the maxilla were included in this study. All patients accepted (125)I seeds implantation after operation, and wore digital model obturators containing (125)I seeds. The prescription dose was 80 Gy. All patients were followed up every 2 months after treatment.</p><p><b>RESULTS</b>The total number of seeds used in these six patients was 189, and 105 seeds were contained in obturators. Radioactive seeds and doses distributed very well as designed in all patients. No tumors recurred after follow up of 12-16 months and there were no severe complications.</p><p><b>CONCLUSIONS</b>It's an effective way to treat malignant tumors with positive excision margin in the maxilla by brachytherapy using digital model obturators which contain (125)I radioactive seeds.</p>

Experimental study on controlling unilateral spine growth by shape memory alloy staple / 中华外科杂志

<p><b>OBJECTIVE</b>To observe the effects that shape memory alloy (SMA) staples implanted to the lateral aspect of the thoracic vertebrae on spinal growth in goats.</p><p><b>METHODS</b>Sixteen goats (age 2 - 3 months) were divided into 3 groups: six in single staple group; six in double staples group and four in control group. Single staples group underwent right-side thoracotomy for exposing the thoracic spine through the eighth rib. Five SMA staples were placed laterally into vertebral bodies of T(6 - 11) spanning discs. Double staples group underwent the same operation. Laterally directed 10 SMA staples were placed into vertebrae of T(6 - 11) spanning discs and two staple spanning each disc. The last four goats in control groups just only underwent right-side thoracotomy. In the next 4 months after operation, radiographs were taken to observe the spinal growth every month.</p><p><b>RESULTS</b>The radiographic analysis demonstrated scoliosis of 12.83 degrees +/- 12.17 degrees in single staple group and 12.00 degrees +/- 3.22 degrees in double staple group after 2 months of the operation. Cobb angle of 6.00 degrees +/- 4.94 degrees and 25.17 degrees +/- 3.71 degrees were observed in the two groups respectively after 4 months of operation, as compared with 0 degrees in the control groups. Only 2 goats developed kyphosis.</p><p><b>CONCLUSIONS</b>Compression between vertebral bodies by SMA staples can depress spinal growth in the same side and greater compression result in larger curves.</p>

A preliminary discussion of angiographic anatomy and variations of rabbit hepatic vessels and catheterization methods of hepatic artery / 介入放射学杂志

Objective To study the normal angiographic anatomy and variations of rabbit hepatic vessels,and explore the optimal method for hepatic artery catheterization.Methods 30 rabbits were divided into two groups randomly.Modified surgical method and interventional method were used to catheterize hepatic artery respectively,and followed by angiography to demonstrate the normal anatomy and variations of rabbit celiac artery,hepatic artery and portal vein.Results The route and distribution of rabbit celiac artery and hepatic artery were very different from human's.The commonly seen variation showed the differences in branching bifurcation of hepatic-gastric artery,with the incidence of 13.3%.The rates of successfully hepatic artery catheterization with surgical and interventional methods were 86.6%(13/15)and 80%(12/15)respectively (P＞0.05).The surgical method will not be successful,whenever there's variation.Conclusion The normal anatomy and variation of rabbit celiac artery and hepatic artery are quite different from human's.Both surgical and interventional catheterizations could be rather successful but possessing advantages and disadvantages of each its own.

Nonexpressor of pathogenesis-related genes 1 (NPR1): a key node of plant disease resistance signalling network / 生物工程学报

The NPRI (nonexpressor of pathogenesis-related genes (1) gene, firstly cloned in Arabidopsis thaliana, is a key gene involved in regulation of plant disease resistance. It plays a pivotal role not only in systemic acquired resistance (SAR) and induced systemic resistance (ISR), but also in basic resistance and resistance (R) gene-dependent resistance. NPR1 monomerization induced by enhanced reducing condition after oxidative burst, and the accumulation of NPR1 monomers in the nuclei, are required and enough for expression of PR (pathogenesis-related) genes and SAR. NPR1 regulates PR gene expression through interaction with TGA transcription factors (TF). As a cross-talk point of a variety of defense signaling pathways, probably through direct or indirect interacting with some WRKY TFs and a NPR1-like protein NPR4, NPR1 is essential in balancing salicylic acid- and jasmonic acid- dependent signal transduction pathways, which is achieved through an unknown mechanism in the cytosol. The possible application of NPR1 in plant protection is also discussed in this review.