Aims To construct the N-terminal Strep-tagged ( NS-tagged) fusion protein expression vector, and to apply the vector to express NS-tagged fusion proteins of Chlamydia RNA polymerase subunit. Meth-ods By using PCR method, NS fusion protein tag and a new multiple cloning sites (MCS) were inserted into pET21c-DH plasmid by primers to replace the original T7 protein tag and MCS. The newly introduced Not I cutting site was chosen for self-ligation of PCR prod-uct. Then, the cyclized PCR product was transformed into DH-5α competent cells. The positive clones were selected by PCR and sequencing. To get NS-tagged fu-sion proteins of chlamydial RNA polymerase subunits, the α, β and β′ subunits were inserted between BamH I and Sal I cutting sites of the newly constructed ex-pression vector. Then, the NS-α, NS-β and NS-β′ ex-pression vectors were transformed into Arctic Express expression cells. The fusion protein expression statuses of transformed cells were identified by Commassie blue staining and Western blot. Results The NS-tagged fusion protein expression vector pET21c-NS-MCS was successfully constructed, and NS-α, NS-β and NS-β′fusion proteins were obtained by using this newly con-structed expression vector. Conclusions In this pro-ject, we constructed an NS-tagged fusion protein ex-pression vector and applied it to express NS-α, NS-βand NS-β′ fusion proteins. Our study can lay a solid foundation for the study of transcriptional regulation of Chlamydia genes.

Objective To report a retroperitoneal laparoscopic surgery for ureteropelvic junction obstruction (UPJO) by double renal veins.Methods A 28-year-old male patient with left low back pain for 6 months was diagnosed as left hydronephrosis and UPJO.A ureteral stent had been placed 3 months before and failed to improve hydronephrosis,so the ureteral stent was pulled out.CT scan showed that left UPJ went through the two renal veins,suggesting UPJO.Nephrogram showed that left GFR and right GFR were 35 ml/min and 34 ml/min,respectively.These results indicated mechanical obstruction of left upper urinary tract.The patient underwent retroperitoneal laparoscopic Anderson-Hynes dismembered pyeloplasty.Results The surgical procedure was successful.Two left renal veins were found,and the ventral one was in front of ureter,compressing the ureter.An aberrant renal artery went into left kidney with the ureter.0.5 cm stenosis of ureteropelvic junction was excised,and pyeloplasty was performed.A ureteral stent was placed into the ureter,then the pelvis and the ureter were sew up in front of the ventral renal vein.The surgical time was 240 min,and blood loss was 50 ml.Postoperative hospital stay time was 4 d.During 4 months' follow up,hydronephrosis was attenuated significantly.Conclusion Retroperitoneal laparoscopic surgery for UPJO with aberrant two renal vein might be a minimally-invasive and effective procedure.

Objective To review the clinical characteristics of paraganglioma of the urinary bladder with 5 cases reprt.Methods The clinical data of 5 patients (2 males and 3 females,age 23-68 years)with paraganglioma of the urinary bladder were reported.Two cases were diagnosed by ultrasonography during health examination,1 case was found by hematuria,1 had difficulty of voiding,and 1 presented with palpitation,chest discomfort while urination.Two cases were clinical diagnosed as bladder paraganglioma,1case urachal carcinoma,and 2 cases bladder tumor.Cystoscopy showed a protruding tumor within the bladder or bladder had compressed changes.One case of tumor located in the triangle,1 in the posterior wall,1in the top,2 in the anterior wall.Three cases of biopsy were negative.Three cases of preoperative endocrine examinations showed norepinephrine significantly higher.Results Laparoscopic partial cystectomy was performed in 3 cases,open partial cystectomy in 1 case,and transurethral resection of bladder tumor (TURBT) in 1 case.One case had the complication of stress cardiomyopathy during TURBT,3 cases found intraoperative hypertensive crisis.The bleeding volume was 20-800 ml (average 126 ml),and I case received blood transfusion.During the follow-up period for 3-48 months,the blood pressure was normal,and no recurrence was found.Conclusions Bladder paraganglioma is uncommon and easily misdiagnosed.For the patients with bladder tumor,accompanied by changes in blood pressure,palpitations during urination should be highly suspicious of bladder paraganglioma.Partial cystectomy is the main treatment method.