Objective To screen and isolate the radioresistance related genes of IRM-2 mice.Methods cDNA library of IRM-2 mice was constructed by SMART technique.Total RNA was isolated from spleens of IRM-2 male mice.The first-strand cDNA was synthesized by using PowerScript reverse transeriptase,and double-strand cDNA was synthesized and amplified by long PCR.The PCR products were purified,digested with restriction enzyme Sfi I.The ds-cDNA fragment lessthan 500 bp was fractionated and ligated to the Sfi I-digested pDNR-LIB vector.The ligation mixture was transformed into E.coil DH5α by electroporution transformation to generate the unamplified cDNA library.The quality of cDNA library was identified by PCR technique.130 clones from cDNA library were sequenced and compared with GenBank database.Results The cDNA library contained 2.25 x 106 independent clones with an average insert size of 1.2 kb.The ratio of recombination and full-length was 95% and 55%,respectively.21 pieces of EST sequences from cDNA library were not the same as the known mice genes and registered into GenBank EST database,with registered number DW474856-DW474876.Conclusions cDNA library of IRM-2 mice has been constructed successfully.21 pieces of EST implies that radioresistance correlative genes may be in IRM-2 mice,which will lay a foundation for isolating and identifying radioresistance related genes in further study.

OBJECTIVE:To study antibacterial activities of meropenem(MPN)combined with cefoperazone sulbactam(SCF) to 3 kinds of multidrug resistance (MDR) Gram-negative bacteria. METHODS:Each 50 strains of MDR-Escherichia coli (MDR-EC),MDR-Klebsiella pneumoniae (MDR-KPN) and MDR-Acinetobacter baumannii (MDR-AB) were isolated from spu-tum,blood,urine,ascites or drainage specimens of patients during Jan. to Dec. in 2016 from the affilidated hospital of Taishan medical university. The agar dilution method and board method were used to determine MIC50,MIC90 and MICG of MPN,SCF, MPN+SCF to MDR-EC,MDR-KPN,MDR-AB and calculate fractional inhibitory concentration (FIC). Drug sensitivity test was conducted by K-B disk method. RESULTS:In terms of the MICG to MDR-EC,MDR-KPN,MDR-AB,MPN alone were respec-tively 36.82,82.45,34.32 μg/mL;SCF alone were respectively 42.14,112.67,24.11 μg/mL;MPN combined with SCF were re-spectively 25.97,56.64,11.36 μg/mL. In terms of MICG to MDR-EC,MDR-KPN,MICG showed that MPN+SCF0-0.5 (78.00%),>0-0.5(72.00%),>0.5-1.0 (82.00%). CONCLUSIONS:MPN combined with SCF can effectively improve antibacterial activities to MDR Gram-negative bac-teria as MDR-EC,MDR-KPN,MDR-AB. MPN combined with SCF has synergistic effects.