AIM: To clone and express mouse canstatin (m canstatin)cDNA and provide a basis for the further research on its anti-angiogenic activity and potential application for cancer therapy. METHODS: Total RNA was extracted from mouse liver tissue by Trizol Reagent, and mouse canstatin cDNA was amplified by RT- PCR, then cloned into vector pMD18-T for sequencing. pET30a(+)-m canstatin recombinant plasmid was constructed and expressed in E.coli BL21 with induction of IPTG. RESULTS: Mouse canstatin cDNA is 684 bp coding 227 amino acids. The sequences of both cDNA and amino acid share high homology with human canstatin, with cDNA identity at 89% and amino acids identity at 96% to human canstatin. In the present study, pET30a(+)-m canstatin recombinant plasmid was expressed in E.coli BL21. CONCLUSION: Mouse canstatin cDNA has been cloned for the first time. Constructed pET30a(+)-m canstatin recombinant plasmid is highly expressed in E.coli BL21.

Objective To evaluate the application value with Energy Spectrum CT multi -parameter quanti-tative value in differentiating pulmonary occupying lesions (>0.5cm in diameter).Methods Those were retrospec-tively analyzed on 58 cases in pulmonary occupying lesions performed spectrum dual -phase enhanced CT scan and confirmed by pathology,including malignant group 48 cases;10 cases of benign group.Iodine content(IC)was meas-ured in arterial phase(AP)and venous phase (VP)in iodine based on the image and the level of the aorta,and nor-malized iodine concentrations were calculated in the two phases lesions compared with aorta,and the difference between the two normalized iodine concentrations ICD (ICD =NICvp -NICap).To measure the CT value of lesions on 50keV and 100keV energy image,and calculate the energy attenuation curve slope,namely |Hu (100 kev -50kev)/Hu50 |.The differences of NIC,curve slope,and ICD were compared between benign and malignant pulmonary occupying lesions using independent sample t test method.Results In two phase scan,NIC,curve slope of the venous phase and ICD in malignant group were significantly higher than the benign group,(NIC,curve slope of the venous phase and ICD of the malignant group:NICap:0.180 ±0.051,NICvp:0.463 ±0.086,1.696 ±0.475,ICD:0.284 ± 0.071;NIC,curve slope of the venous phase and ICD of the benign group:NICap:0.123 ±0.062,NICvp:0.290 ± 0.119,1.169 ±0.582,ICD:0.166 ±0.073,),but there was no significant difference between the patients with benign and malignant lesions in curve slope of the arterial phase.Conclusion Energy spectrum CT dual -phase enhanced scan can differentiate the nature of benign and malignant pulmonary occupying lesions,and has certain clinical application value.

To establish a RP-HPLC method for the determination of content of sisomicin sulfate and sodium chloride injection. Thermo Aminoglycoside RP 18(4. 6 mm ×150 mm, 3 μm)column was used. The mobile phase consisted of Sodium heptane sulfonate solution(take 6 g of sodium heptane sulfonate, add 0. 1 mol/L potassium dihydrogen phosphate solution and dilute to 1 000 mL, adjust the pH to 1. 5 with phosphoric acid)- acetonitrile(77∶23). The detection wavelength was 205 nm, the flow rate was 1. 0 mL/min. and the column temperature was 35 °C. The separation of sisomicin peaks with related substances and the degradation products was good. The linear range of the peak area with sisomicin was 0. 010 024-1. 002 4 mg/mL(Y=4. 210 2×106 X+9. 107 0×103, r=0. 999 9, n=7), the detection limit was 0. 6 ng, the limit of quantification was 2 ng, and the recovery rate was at 99. 1%-100. 9%(RSD< 1. 0%, n=9). The method is sensitive, exclusive, accurate and suitable for the determination of sisomicin. Compared with the antibiotic microbiological test method, the specificity is better, the confidence interval of the result is narrowed, and the test time is saved.