Objective To evaluate the multi-spiral CT(MSCT)imaging features and classification of renal pelvis carcinoma.Meth-ods 76 patients of renal pelvis carcinoma proved pathologically were analyzed retrospectively,and divided into different types ac-cording to the MSCT features.The MSCT differences for different types were analyzed.Results Most of the tumors showed iso-density or slight hyperdensity (95%)on un-enhanced images,and persistent mild-to-moderate enhancement (91%)in enhanced im-ages.All cases were divided into three types:pelvic mass type in 30 cases (39%),substance invasion type in 25 cases (33%),wall thickening type in 21 cases (28%).All cases were also divided into two types:substance invasion type(25 cases,33%)and renal pelvis type(5 1 cases,67%).The occurrence rate of local low enhancement,whole kidney low enhancement,hydronephrosis,lymph node metastasis and vein tumor thrombus were 80%,20%,48%,52%,1 6% in substance invasion type cases,and 4%,42%, 75%,4%,6% in the renal pelvis type cases,respectivily.Conclusion MSCT multiphase enhancement scanning shows important valuation in the diagnosis and classification of renal pelvis carcinoma.Obvious differences of CT features are showed for different types.The diagnosis accuracy may be improved by the knowledge of substance invasion type.

Aim: To clone and over-express the gene encoding aminoglycoside(AG)phosphotransferase(APH)from clinical MRSA isolates in E.coli and to develop an assay method for the recombinant APH.Methods: The susceptibility of clinical MRSA isolates to AGs was tested by disk diffusion.A nucleic acid sequence encoding APH was amplified from the genomic DNA of an isolate and ligated to expression vector pET-28a,and then trans-formed into E.coli BL21(DE3).After purification of the recombinant protein by affinity chromatography,the phosphorylation activity of the enzyme was determined by ESI-MS and disk diffusion.Flesults: All 6 clinical MRSA isolates were unsusceptible to AGs.After cloning and expression,the recombinant APH was purified to90%.The in vitro activity assay indicated that the recombinant protein could inactivate kanamycin B in the assay mixture within 2 h.Conclusion: The recombinant APH showed excellent enzymatic activity.The assay method was simple and convenient,which may provide the basis of developing a screening model for APH inhibitors.